proot-distro 5.0.0

PRoot-Distro is a lightweight rootless Linux container management utility built around proot.

PRoot-Distro

PRoot-Distro is a utility for managing rootless Linux containers in Termux and on regular Linux hosts. It uses proot to provide a chroot-like environment without requiring root access on the device.

Containers are created by pulling Docker/OCI images directly from Docker Hub or any compatible public registry — or by extracting a local tarball / OCI image archive. The container filesystem is assembled from the image layers and stored locally, ready to be entered at any time.

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Table of contents

1. Introduction
2. Installation
3. Quick start
4. Commands
   • install
   • login
   • run
   • list
   • remove
   • rename
   • reset
   • backup
   • restore
   • copy
   • sync
   • clear-cache
5. How PRoot-Distro works
6. Storage layout
7. Environment variables
8. Shell completions
9. Limitations
10. Donate

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Introduction

PRoot-Distro lets you run a full Linux userland — Ubuntu, Debian, Alpine, Arch, openSUSE, distroless server images, anything available as a Docker/OCI image — on top of Termux on an Android device, or on top of a regular Linux distribution, without root, without a kernel module, and without a Docker daemon.

Typical use cases:

• Running a desktop-class Linux distribution on a phone or tablet.
• Cross-compiling for a different CPU architecture using QEMU user-mode.
• Spinning up server software (Nginx, Nextcloud, PostgreSQL, etc.) on Android by reusing the same OCI images you'd run on a server.
• Trying a distribution non-destructively: install, mess around, proot-distro remove when done.

The CLI is exposed both as proot-distro and the shorter alias pd.

Installation

PRoot-Distro is primarily distributed via Termux's pkg package manager and via PyPI. Python 3.9 or newer is required. The only runtime dependency is proot (and, optionally, a qemu-user-* package for cross-architecture containers).

On Termux (Android)

Install Termux from F-Droid or the Termux GitHub Releases. Then, inside Termux:

pkg install proot-distro

This pulls in proot automatically as a dependency.

To install the latest published version from PyPI instead:

pkg install python proot
pip install proot-distro

On a regular Linux host

# Install proot via your distro's package manager, e.g. on Debian/Ubuntu:
sudo apt install proot python3-pip

pip install proot-distro          # from PyPI
# or
git clone https://github.com/termux/proot-distro
cd proot-distro
pip install .                     # from a local checkout
pip install -e .                  # editable install for development

First-run check

On startup the tool verifies that proot is available. If it isn't:

• On Termux, with an interactive terminal, you are prompted to install it via pkg install -y -q proot.
• Otherwise, an install hint is printed and the program exits.

PRoot-Distro also refuses to run inside another proot (nested proot is not supported by proot itself) and prints a yellow warning if launched as the root user.

Quick start

# Install Ubuntu 24.04 from Docker Hub
proot-distro install ubuntu:24.04

# Start a shell inside the container
proot-distro login ubuntu

# Same thing, but using the short command alias
pd sh ubuntu

# Run a single command and exit
proot-distro login ubuntu -- /bin/uname -a

# List all installed containers
proot-distro list

# Rebuild from scratch (loses all in-container data)
proot-distro reset ubuntu

# Permanently remove a container
proot-distro remove ubuntu

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Commands reference

The pd short alias works everywhere proot-distro does.

Every command supports --help (also -h, --usage), which prints help text laid out for the current terminal width.

install — Install a container

proot-distro install [OPTIONS] (IMAGE or PATH)
Aliases: add, i, in, ins

Pull a Docker/OCI image and create a container from it, or extract one from a local archive file.

Options:

Option	Description
--name NAME	Set a custom local name for the container. Defaults to the image name without tag/registry, or the archive filename without extension. Must start with a letter or digit; may contain only letters, digits, _, ., -. Empty name is rejected.
--architecture ARCH	Override the target CPU architecture. Accepts native names (aarch64, arm, i686, riscv64, x86_64) or Docker platform strings (linux/arm64, linux/amd64, linux/arm/v7, linux/386, linux/riscv64). Defaults to the host CPU.

From a Docker/OCI registry

IMAGE is a standard Docker image reference:

Form	Example
Official image	ubuntu:24.04
Official, no tag (uses latest)	alpine
User image	myuser/myimage:tag
Custom registry	ghcr.io/foo/bar:latest

Custom registries are detected by the first path component containing . or : (i.e. a hostname). Public images on ghcr.io, quay.io, registry.gitlab.com, etc. are pulled with an anonymous Bearer token discovered from each registry's /v2/ challenge.

Layers are cached in $DOWNLOAD_CACHE_DIR/layers/ and reused on subsequent installs. If both the resolved manifest and all of its layers are already in the cache, installation runs fully offline.

Examples:

proot-distro install ubuntu:24.04
proot-distro install alpine:3.21 --name my-alpine
proot-distro install debian:bookworm --architecture aarch64
proot-distro install ghcr.io/myorg/myimage:latest
proot-distro install nextcloud:32

From a local archive

IMAGE can also be a path to a local archive file. A path is recognised only when it starts with /, ./, ../, or ~ — a bare token like ubuntu is always treated as a Docker image, even if a file by that name happens to exist in the current directory.

Two archive formats are supported, auto-detected by reading the first 500 entries of the archive:

• Plain rootfs tarball — a tar archive whose top-level entries form a standard Linux filesystem (bin/, etc/, usr/, …). The tool scores strip levels 0–4 and picks the one that lands the most recognised rootfs directories at the root. Supported compression: gzip, bzip2, xz, lzma, or uncompressed. No manifest.json is written for this format (so reset and run are not available).
• OCI image layout — a tar archive that contains an oci-layout file at its root (as produced by docker save, skopeo copy oci-archive:, or similar tools). Layers are applied in order with full whiteout semantics, layer blobs are cached, and manifest.json is written so reset and run work like with a registry-pulled image.

The container name is derived from the archive filename by stripping known extensions (.tar, .tar.gz, .tgz, .tar.bz2, .tbz2, .tar.xz, .txz, .tar.lzma, .tlzma, .oci.tar, .oci.tar.gz, .oci.tar.xz) and sanitising the result. Use --name to set an explicit name.

Examples:

# Plain rootfs tarball
proot-distro install ./alpine-rootfs.tar.gz

# OCI image layout saved with docker
docker save myimage:latest -o myimage.oci.tar
proot-distro install ./myimage.oci.tar --name myimage

# Explicit name and architecture override
proot-distro install /tmp/debian-arm.tar.xz --name debian --architecture arm

After installation the resolved image tag is shown (e.g. Installing 'ubuntu:24.04'). If the image defines an Entrypoint, a Run entrypoint: proot-distro run <name> hint is printed alongside Start shell: proot-distro login <name>.

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login — Start a shell inside a container

proot-distro login [OPTIONS] CONTAINER [-- COMMAND ...]
Aliases: sh

Spawn an interactive shell (or a custom command) inside an installed container. The -- separator passes a command to run inside the container's login shell (the shell still wraps it, so quoting and redirection inside COMMAND work as expected).

Examples:

# Interactive shell as root
proot-distro login ubuntu

# Interactive shell as a non-root user
proot-distro login ubuntu --user myuser

# Run a single command
proot-distro login ubuntu -- /bin/ls /etc

# Run a shell command string
proot-distro login ubuntu -- bash -c "echo hello"

# Use the short alias
pd login ubuntu

# Inspect the full proot command line without running it
proot-distro login ubuntu --get-proot-cmd

Options always available:

Option	Description
--user USER	Log in as USER (default: root). For containers without /etc/passwd, only a numeric UID or the literal root is accepted.
--redirect-ports	Redirect privileged ports 1–1023 to higher numbers (22 → 2022, 80 → 2080, …). The offset is hardcoded inside proot.
--shared-home	Bind the host home directory into the container (mounted at /root for the root user, at the user's home otherwise; for termux-type containers it goes to /data/data/com.termux/files/home).
--termux-home	Synonym for --shared-home (mutually exclusive with it).
--shared-tmp	Bind the host $PREFIX/tmp to /tmp inside the container (Termux only; skipped for termux-type containers).
--shared-x11	Bind $PREFIX/tmp/.X11-unix to /tmp/.X11-unix (Termux only; skipped for termux-type containers).
--bind SRC[:DST]	Bind a custom path (repeatable). SRC is resolved via os.path.abspath. DST, when given, must be an absolute path (relative destinations are rejected). Overlap with an existing destination emits a warning but the bind is still added.
--emulator PATH	Override the QEMU emulator binary for cross-arch containers. PATH must be executable. Only QEMU user-mode and Blink are known to work.
--kernel STRING	Customize the kernel release string reported by uname -r. Default: 6.17.0-PRoot-Distro.
--hostname STRING	Customize the hostname inside the container. Default: localhost.
--work-dir PATH	Set the initial working directory. Default: the user's home directory.
--env VAR=VALUE	Set an environment variable in the guest (repeatable). Wins over image-defined Env and the baseline defaults.
--get-proot-cmd	Print the fully assembled env + proot command line (escaped, with line continuations) and exit without running.

Options available only on Termux (Android):

Option	Description
--isolated	Skip non-essential host bindings (Android system dirs, Termux $HOME, /sdcard, Termux app paths). Keeps the link2symlink/sysvipc/kill-on-exit proot extensions and the kernel-release override. Mutually exclusive with --minimal.
--minimal	Bare-minimum proot: only /dev, /proc, /sys are bound, --sysvipc is disabled, no fake /proc stubs, no --kernel-release. Guest env contains only your --env entries plus TERM/COLORTERM. Mutually exclusive with --isolated.
--no-link2symlink	Disable proot's hard-link emulation. Only safe on devices with SELinux in permissive mode.
--no-sysvipc	Disable System V IPC emulation. Only useful on kernels that already implement it.
--no-kill-on-exit	Wait for all child processes before exiting the session.

Host bindings (Termux, default mode)

Without --isolated or --minimal, the following host paths are mounted inside the container when present and readable:

/apex
/data/app
/data/dalvik-cache
/data/data/<termux-app-package>
/linkerconfig/com.android.art/ld.config.txt
/linkerconfig/ld.config.txt
/odm
/product
/sdcard
/storage/emulated/0
/storage/self/primary
/system
/system_ext
/vendor

Plus, for normal-type containers, the Termux $PREFIX is bound at its original path inside the guest so Termux utilities (termux-api, pkg, etc.) are reachable.

Guest environment

The host's environment is not carried into the guest. PRoot-Distro builds a clean environment dict and passes it to os.execvpe("proot", …). Precedence (later entries win):

1. Baseline: PATH (from DEFAULT_PATH_ENV), MOZ_FAKE_NO_SANDBOX=1, PULSE_SERVER=127.0.0.1 (Termux only).
2. Image-defined Env from manifest.json. Cannot override Android system vars, MOZ_FAKE_NO_SANDBOX, PULSE_SERVER, TERM, or COLORTERM.
3. Android system vars (ANDROID_*, BOOTCLASSPATH, etc.), Termux only, when not --isolated and not --minimal.
4. Your --env VAR=VALUE entries.
5. HOME, USER, TERM (defaulting to xterm-256color), COLORTERM (only when set on the host).

After the precedence pass, $PREFIX/bin is appended to PATH so Termux host tools stay reachable inside the guest. A snippet at /etc/profile.d/termux-profile.sh re-applies every login-time environment variable (PATH, image Env, Android system vars, --env flags) after the distro's /etc/profile resets the environment on login — without it, running su - someuser inside the container would silently drop those values. Per-session vars (HOME, USER, TERM, COLORTERM) and proot-internal vars are excluded.

In --minimal mode steps 1–3 and the PATH post-processing are skipped; only your --env entries plus TERM/COLORTERM are exported.

Legacy migration

If a container was created by an older version of PRoot-Distro and its rootfs is still at the legacy path ($RUNTIME_DIR/installed-rootfs/<name>), login automatically migrates it to the new layout ($RUNTIME_DIR/containers/<name>/rootfs) on first use, including rewriting any internal proot link2symlink (l2s) symlinks. This may take a while on large containers.

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run — Run the image-defined entrypoint

proot-distro run [OPTIONS] CONTAINER [-- ARG ...]

Run the Entrypoint and/or Cmd defined in the container's Docker image manifest. This is equivalent to docker run: the container starts, executes the image-defined command, and exits when it finishes.

run requires that the container was installed from an OCI image (plain tarball installs have no manifest.json and therefore no recorded Entrypoint/Cmd).

Entrypoint and Cmd resolution:

Image	Args after --	Inner command
Entrypoint + Cmd	(none)	Entrypoint + Cmd
Entrypoint + Cmd	ARGS	Entrypoint + ARGS (Cmd replaced)
Only Cmd	(none)	Cmd
Only Cmd	ARGS	ARGS (Cmd replaced)
Only Entrypoint	(none)	Entrypoint
Only Entrypoint	ARGS	Entrypoint + ARGS
Neither	(none)	Error
Neither	ARGS	ARGS

When --work-dir is not given, run uses the image's WorkingDir (falling back to / if it is empty).

run accepts the same options as login (--user, --bind, --isolated, --minimal, --env, --shared-tmp, --shared-x11, --emulator, --get-proot-cmd, etc.). See proot-distro login --help.

Examples:

# Run the image's default entrypoint
proot-distro run hello-world

# Run with port redirection (so 80 → 2080)
proot-distro run nextcloud --redirect-ports

# Pass arguments to the entrypoint (overrides image Cmd)
proot-distro run ubuntu -- /bin/echo hi

# Print the proot command line without executing
proot-distro run nextcloud --get-proot-cmd

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list — List installed containers

proot-distro list
Aliases: li, ls

Show all installed containers (subdirectories of containers/ that have a rootfs/). When none are installed, an install suggestion is printed.

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remove — Delete a container

proot-distro remove [OPTIONS] CONTAINER
Aliases: rm

Permanently delete the specified container and all its data. This cannot be undone and is not confirmed. Permissions of chmod-000'd files are fixed on the fly so the rootfs can always be cleared.

Option	Description
-v, --verbose	Log each deleted file.

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rename — Rename a container

proot-distro rename OLDNAME NEWNAME

Rename a container from OLDNAME to NEWNAME. Also rewrites every proot link2symlink (l2s) symlink whose target is still pointing into the old rootfs path, so hardlinks remain valid. This may take a while on large containers.

For data-integrity reasons, CTRL-C and CTRL-\ are intercepted during the l2s rewrite. The signal is replaced with a one-line warning; the rewrite continues until done.

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reset — Reinstall a container from scratch

proot-distro reset CONTAINER

Remove the container rootfs and reinstall it from the Docker image recorded at install time. All data inside the container is lost.

The image reference and target architecture are read from containers/<name>/manifest.json. If that file is missing, the command exits with an error — reset is supported for OCI image installs only (plain rootfs tarballs cannot be re-pulled).

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backup — Archive a container

proot-distro backup [OPTIONS] CONTAINER
Aliases: bak, bkp

Create a TAR archive of the container. The archive contains <name>/manifest.json (when present) and <name>/rootfs/.

Options:

Option	Description
--output FILE	Write to FILE instead of stdout. Refuses to overwrite an existing file.
--compress TYPE	Force compression: gzip, bzip2, xz, or none. Overrides extension-based detection.
-v, --verbose	Log each archived file.

When --output is given, the compression algorithm is inferred from the file extension (.tar.gz, .tgz, .tar.bz2, .tbz2, .tar.xz, .txz, .tar.lzma, .tlzma, or plain .tar) unless --compress overrides it. Unsupported extensions (.tar.zst, .tzst, .tar.lz4, .tar.lz) are rejected.

Without --output, the archive is written to stdout, uncompressed by default. Stdout cannot be a TTY (you must redirect or pipe).

File ownership in the archive is zeroed (uid=gid=0, no uname/gname). Block devices, character devices, FIFOs, and sockets are silently skipped. Symlinks to directories are stored as single entries. Before archiving, the rootfs permissions are fixed up so chmod-000'd subtrees become at least readable by the owner.

backup is TTY-safe when piping into an interactive consumer (e.g. gpg -c with a pinentry prompt): all progress output is suppressed while the downstream process holds the TTY in non-canonical/no-echo mode, then resumes once the TTY returns to normal.

Examples:

# Create a compressed backup
proot-distro backup ubuntu --output ubuntu.tar.xz

# Pipe to another command
proot-distro backup ubuntu | gzip > ubuntu.tar.gz

# Encrypt with GPG (pinentry-safe)
proot-distro backup ubuntu | gpg -c > ubuntu.tar.gpg

# Verbose listing while archiving
proot-distro backup ubuntu --output ubuntu.tar --verbose

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restore — Restore a container from a backup

proot-distro restore [OPTIONS] [BACKUP_FILE]

Restore a container from a TAR archive. When BACKUP_FILE is omitted, archive data is read from stdin.

Compression is detected automatically — tarfile's r|* auto-detect handles file input; for stdin, the first 6 magic bytes are peeked to identify gzip / bzip2 / xz / lzma streams.

Options:

Option	Description
-v, --verbose	Log each extracted file.

Archive format requirements:

• Files must be stored under a subdirectory named after the container (<name>/manifest.json, <name>/rootfs/...). Bare-root archives (e.g. tar of a rootfs without any leading directory) are rejected.
• If manifest.json is not present in the archive, the container is restored without it (login still works, but reset and run will not).
• Legacy archives (installed-rootfs/<name>/...) are accepted and automatically re-rooted to the new layout.

The existing rootfs for each container in the archive is cleared recursively on the first entry seen for that container. Hard links are resolved using the archive's own paths and recreated with os.link.

restore is TTY-safe when reading from a pipe that involves an interactive producer (gpg -d archive.gpg | proot-distro restore): progress output stays silent while the upstream pinentry holds the TTY, then resumes once the TTY returns to normal.

Examples:

# Restore from a file
proot-distro restore ubuntu.tar.xz

# Restore from stdin
cat ubuntu.tar.xz | proot-distro restore

# Decrypt + restore in one pipeline
gpg -d ubuntu.tar.gpg | proot-distro restore

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copy — Copy files to or from a container

proot-distro copy [OPTIONS] [CONTAINER:]SRC [CONTAINER:]DEST
Aliases: cp

Copy files between the host filesystem and a container rootfs, or between two containers. Paths inside a container are prefixed with the container name and a colon: ubuntu:/etc/resolv.conf.

Option	Description
-r, --recursive	Copy directories recursively (preserves symlinks).
-m, --move	Move instead of copying (deletes source after success).
-v, --verbose	Log each copied file.

Directories . and .. are accepted only as source, not as destination. Glob patterns are not supported (rely on the shell).

Examples:

# Copy a local file into a container
proot-distro copy ./file.txt ubuntu:/root/file.txt

# Copy a file out of a container
proot-distro copy ubuntu:/etc/resolv.conf ./resolv.conf.bak

# Copy between two containers
proot-distro copy arch:/etc/pacman.conf ubuntu:/tmp/pacman.conf

# Recursive copy of a local directory
proot-distro copy --recursive ./myapp ubuntu:/opt/myapp

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sync — Synchronize files to or from a container

proot-distro sync [OPTIONS] [CONTAINER:]SRC [CONTAINER:]DEST

Synchronize SRC to DEST, copying only files that differ. Both paths may be plain host paths or container:path references. Always recursive — no flag needed.

Comparison method:

Mode	What is compared
Default	File size and integer modification time
--checksum	File size and CRC32 checksum

Behavior:

• Symlinks are copied as-is (target not followed).
• Hard links become independent file copies (no inode tracking).
• Block/char devices, FIFOs, and sockets are silently skipped.
• File ownership is never changed (chown is not called).
• Access modes and modification timestamps are preserved.
• Regular files are written atomically (.~pd_sync temp file → os.replace) so a partial copy never leaves a corrupt destination.
• If a source file is not readable, a warning is printed and it is skipped.
• If the destination lacks write permission, sync first attempts to chmod it. If that also fails, the command exits with an error.

Option	Description
--checksum	Compare by size + CRC32 instead of size + mtime (slower, more strict).
--delete	Remove destination files and directories that have no counterpart in the source. Applied after the sync pass; only effective when source is a directory.
-v, --verbose	Log each synced or deleted entry. Suppresses the progress bar.

Examples:

# Sync a local directory into a container
proot-distro sync ./app ubuntu:/opt/app

# Sync a directory out of a container
proot-distro sync ubuntu:/etc ./backup/etc

# Use checksum-based comparison
proot-distro sync --checksum ./data ubuntu:/data

# Make destination match source exactly (delete extras)
proot-distro sync --delete ./app ubuntu:/opt/app

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clear-cache — Delete the download cache

proot-distro clear-cache
Aliases: clear, cl

Remove all cached Docker image layers and resolved manifests from $DOWNLOAD_CACHE_DIR. Disk space freed is reported after the operation in human-readable units.

Option	Description
-v, --verbose	Log each deleted file.

After clear-cache, the next install (or reset) of an image requires network access again, and layers must be re-downloaded and re-verified.

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How PRoot-Distro works

PRoot-Distro is a thin orchestration layer around two primary building blocks:

1. OCI registry client

The install command speaks the standard OCI Distribution protocol directly over urllib:

• Public images on Docker Hub require no flags (e.g. ubuntu:24.04).
• Public images on other registries are addressed by full reference (e.g. ghcr.io/myorg/myimage:tag). PRoot-Distro probes https://<registry>/v2/, follows the OCI Bearer auth challenge, and pulls an anonymous token.
• Manifest lists are resolved to the platform that matches your CPU (or the --architecture override).
• Each layer blob is downloaded with its SHA-256 verified before being promoted into the cache. Cross-host redirects (Docker Hub → CDN) have their Authorization header stripped to satisfy CDNs that reject bearer tokens.
• Layer blobs and the resolved single-arch manifest are cached locally. Subsequent installs of the same image are fully offline.

Layers are applied in order on top of an empty rootfs directory, with full OCI whiteout semantics (.wh..wh..opq and .wh.<name> markers). Hard links are materialised as copies for self-containment. Block devices, character devices, and FIFOs are skipped.

After all layers are applied, PRoot-Distro adds three small fixups when the image has /etc/:

• /etc/resolv.conf is replaced with Google DNS (8.8.8.8 / 8.8.4.4).
• /etc/hosts is populated with a minimal localhost mapping.
• The host's Termux/Android user is registered as aid_<name> in /etc/passwd, /etc/shadow, /etc/group, and /etc/gshadow so Android's UID-based permissions work inside the container.

The full OCI manifest and image config are saved to containers/<name>/manifest.json. This lets reset re-pull the exact same image later, and run know what to execute by default.

A local archive also can be used with install command:

• A plain rootfs tarball (alpine.tar.gz, debian.tar.xz, etc.): the leading path component count is detected automatically by scoring directory names like bin, usr, etc, var.
• An OCI image layout (as produced by docker save or skopeo copy oci-archive:): detected by the presence of an oci-layout file at the archive root. The selected platform's layers are extracted into the cache and applied with the same code path used for registry pulls.

2. The proot utility

proot is a user-space implementation of chroot, mount --bind, and binfmt_misc. It uses Linux's ptrace mechanism to intercept system calls made by the guest process and rewrite filesystem paths on the fly. The result is a chroot-like environment that does not need root privileges.

When you run proot-distro login ubuntu, PRoot-Distro execs into a proot command line that looks roughly like:

env PATH=… HOME=/root … \
  proot --kill-on-exit --link2symlink --sysvipc \
        --kernel-release=… -L \
        --change-id=0:0 \
        --rootfs=/…/containers/ubuntu/rootfs --cwd=/root \
        --bind=/dev --bind=/proc --bind=/sys \
        --bind=/storage --bind=/system --bind=/apex … \
        /bin/sh -l

You can see this exact command for any container by adding the --get-proot-cmd flag to login or run.

Cross-architecture support

Architectures supported as containers: aarch64, arm, i686, x86_64, riscv64. The host CPU is detected via os.uname().machine. Cross-architecture execution uses QEMU user-mode via proot's -q flag. The matching qemu-user-<arch> package must be installed on the host. 32-bit guests run natively on 64-bit hosts when the kernel supports PER_LINUX32 (probed via ctypes).

Container architecture is detected automatically at every login by reading ELF headers of common shell binaries inside the rootfs — there is no separate config file to remember.

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Storage layout

All runtime data is stored under $RUNTIME_DIR:

• Termux: $TERMUX__PREFIX/var/lib/proot-distro/, where TERMUX__PREFIX defaults to /data/data/com.termux/files/usr.
• Regular Linux: $XDG_DATA_HOME/proot-distro/ (default ~/.local/share/proot-distro/).

The OCI download cache ($DOWNLOAD_CACHE_DIR) is under $RUNTIME_DIR on Termux, and under $XDG_CACHE_HOME/proot-distro/ (default ~/.cache/proot-distro/) on a regular Linux host.

Path	Contents
containers/<name>/rootfs/	Container root filesystem
containers/<name>/manifest.json	Image reference, arch, full OCI manifest, full image config
containers/<name>/rootfs/.l2s/	Proot link2symlink (l2s) backing store (created on first login)
dlcache/layers/ (Termux) or $XDG_CACHE_HOME/proot-distro/layers/	Cached OCI layer blobs
dlcache/manifests/ (Termux) or …/manifests/	Cached resolved single-arch manifests
installed-rootfs/<name>/	Legacy layout; auto-migrated by login.

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Environment variables

Variable	Effect
TERMUX__PREFIX	Override Termux prefix path; drives PREFIX and RUNTIME_DIR on Termux. Defaults to /data/data/com.termux/files/usr.
TERMUX__HOME	Override the Termux home path used for --shared-home and the default storage bindings. Defaults to /data/data/com.termux/files/home.
TERMUX_APP__PACKAGE_NAME	Override the Termux app package (default com.termux); used for --bind=/data/data/<pkg>/....
TERMUX_APP__APP_VERSION_NAME, TERMUX_VERSION	Either one (when set) counts as one of the indicators that flips on Termux mode in _detect_termux().
XDG_DATA_HOME	On non-Termux hosts, base for $XDG_DATA_HOME/proot-distro/. Defaults to ~/.local/share.
XDG_CACHE_HOME	On non-Termux hosts, base for $XDG_CACHE_HOME/proot-distro/. Defaults to ~/.cache.
PD_FORCE_NO_COLORS	When set to any value, disables ANSI colors in PRoot-Distro's own output.
PROOT_NO_SECCOMP	Inherited and forwarded to proot. Set to 1 if login fails with seccomp-related errors on the host kernel. Skipped in --minimal mode.
PROOT_DUMP, PROOT_VERBOSE	Inherited and forwarded to proot for debugging. Skipped in --minimal mode.
COLUMNS	Fallback terminal width for --help rendering.
TERM, COLORTERM	Inherited from the host and exported into the guest (always; even in --minimal). In normal-type containers, TERM defaults to xterm-256color when unset on the host.

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Shell completions

The packaged distribution installs completion scripts for Bash, Zsh, and Fish to the standard locations:

• share/bash-completion/completions/proot-distro
• share/zsh/site-functions/_proot-distro
• share/fish/vendor_completions.d/proot-distro.fish

All three scripts complete both proot-distro and the short alias pd.

If your shell does not pick them up automatically, copy them by hand:

# Bash, current user
mkdir -p ~/.local/share/bash-completion/completions
cp proot_distro/completions/proot-distro.bash \
   ~/.local/share/bash-completion/completions/proot-distro

# Zsh, current user
mkdir -p ~/.zsh/completions
cp proot_distro/completions/_proot-distro ~/.zsh/completions/_proot-distro
# and add 'fpath=(~/.zsh/completions $fpath)' to .zshrc before compinit

# Fish, current user
mkdir -p ~/.config/fish/completions
cp proot_distro/completions/proot-distro.fish \
   ~/.config/fish/completions/proot-distro.fish

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Limitations

PRoot limitations

• Performance: proot intercepts every system call via ptrace. Filesystem-heavy workloads (compilation, package managers) are noticeably slower than native execution.
• Kernel features: features that depend on Linux kernel modules (FUSE, specific iptables targets, custom cgroup hierarchies, etc.) do not work.
• No real root: proot uses UID/GID remapping to fake root. Programs that genuinely need kernel-level root (sudo, mount of real filesystems, iptables, etc.) will fail.
• No background services: starting service supervisors (systemd, OpenRC, socket-activated daemons) is generally not possible. You can run individual long-running processes, but a full init system is out of scope.
• No cgroups / namespaces: features that need real Linux kernel namespaces (unshare, container-in-container, network namespaces) do not work — proot is path translation, not kernel isolation.
• seccomp: some Android kernels restrict ptrace calls used by proot via seccomp policies. If login fails with seccomp-related errors, set PROOT_NO_SECCOMP=1.
• No nesting: PRoot-Distro refuses to run inside another proot, because proot itself cannot trace a process already being traced.

PRoot-Distro limitations

• Public registries only: registry authentication is not implemented. Only public Docker Hub images and public OCI registries are supported. Private images return an explanatory error from install.
• No zstd-compressed layers: Python's tarfile module does not support zstd. Images using zstd-compressed layers (some newer Docker Hub images) fail to install with an explicit error. Try a different image or an older tag.
• No image building: PRoot-Distro consumes existing OCI images; it does not build them. Use docker build / buildah / nerdctl on a full Linux host to produce one, then docker save -o myimage.oci.tar myimage:tag and proot-distro install ./myimage.oci.tar.
• No live state migration: backup/restore archive the rootfs and the OCI manifest, but in-memory state of running processes is not preserved.
• Cross-architecture Termux-type containers are not supported: the host and the container share the same Termux prefix path, so QEMU emulation cannot hide the host's architecture-specific binaries.
• Termux-only flags on non-Termux hosts: --isolated, --minimal, --no-link2symlink, --no-sysvipc, and --no-kill-on-exit are not exposed by argparse when running outside Termux. Most are Android-specific in spirit, and on a regular Linux host the default behavior is already isolated in the sense that there are no Android bindings to drop.

---

Donate

Support is important to keep the project up in a long term. I'm grateful for any amount of tip in cryptocurrency:

Bitcoin:

bc1qxuwtc0sfjt43n3sufck6s0gaeand8eaeguajxs

Ethereum:

0x1F5196A5b0120D4a66FCAABBe71728239B06EC12

Tron:

TEJiwRMMGV1JXvRYDRVJ1qw7kFgskEk3sJ

Recipient: the author of PRoot-Distro, @sylirre

Issues and contributing

• Bug reports: https://github.com/termux/proot-distro/issues
• License: GPL-3.0-only. See LICENSE.