Troubleshooting the Build

This page covers all troubleshooting methods and tips for our build system.

(You must read this page before)


When you run or, the Linux tools and libraries required to support the toolchain and build all recipes are installed. Then the redox project is downloaded from the Redox GitLab server. The redox project does not contain the system component sources, it only contains the build system. The cookbook subproject, which contains recipes for all the packages to be included in Redox, is also copied as part of the download.

Not all Linux distributions are supported by, so if you are on an unsupported distribution, try the script for Podman builds, or have a look at the script and try to complete the setup manually.

If you want to support your Unix-like system without Podman, you can try to install the Debian/Ubuntu package equivalents for your system from your package manager/software store, you can see them on this function of the script.

The script and redox-base-containerfile covers the build system packages needed by the recipes at demo.toml

(Note that some systems may have environment problems hard to fix, on these systems Podman will avoid some headaches)


If you did not use or to setup your environment, you can download the sources with:

git clone --origin upstream --recursive

If you are missing the cookbook project or other components, ensure that you used the --recursive flag when doing git clone. Ensure that all the libraries and packages required by Redox are installed by running -d or, if you will be using the Podman build, -d.

Building The System

When you run make all, the following steps occur.

.config and mk/

  • make scans .config and mk/ for settings, such as the CPU architecture, configuration name, and whether to use Podman during the build process. Read through Configuration Settings to make sure you have the settings that are best for you.


The Redox toolchain, referred to as prefix because it is prefixed with the CPU architecture name, is downloaded and/or built. Modified versions of cargo, rustc, gcc and many other tools are created. They are placed in the prefix directory.

If you have a problem with the toolchain, try rm -rf prefix, and everything will be reinstalled the next time you run make all or make rebuild.


If enabled, the Podman environment is set up. Podman is recommended for unsupported systems.

If your build appears to be missing libraries, have a look at Debugging your Podman Build Process. If your Podman environment becomes broken, you can use podman system reset and rm -rf build/podman. In some cases, you may need to do sudo rm -rf build/podman.

Manual Configuration

If you have problems setting Podman to rootless mode, use these commands:

(These commands were taken from the official Podman rootless wiki and Shortcomings of Rootless Podman, thus it could be broken/wrong in the future, read the wiki to see if the commands match, we will try to update the method to work with everyone)

  • Install the podman, crun, slirp4netns and fuse-overlayfs packages on your system.
  • podman ps -a - this command will show all your Podman containers, if you want to remove all of them, run podman system reset.
  • Take this step if necessary (if the Podman of your distribution use cgroup V2), you will need to edit the containers.conf file on /etc/containers or your user folder at ~/.config/containers, change the line runtime = "runc" to runtime = "crun".
  • Execute cat /etc/subuid and cat /etc/subgid to see user/group IDs (UIDs/GIDs) available for Podman.

If you don't want to edit the file, you can use this command:

sudo usermod --add-subuids 100000-165535 --add-subgids 100000-165535 yourusername

You can use the values 100000-165535 for your user, just edit the two text files, we recommend sudo nano /etc/subuid and sudo nano /etc/subgid, when you finish, press Ctrl+X to save the changes.

  • After the change on the UID/GID values, execute this command:
podman system migrate
  • If you have a network problem on the container, this command will allow connections on the port 443 (without root):
sudo sysctl net.ipv4.ip_unprivileged_port_start=443
  • Hopefully, you have a working Podman build now.

(If you still have problems with Podman, read the Troubleshooting chapter or join us on the chat)

Let us know if you have improvements for Podman troubleshooting on the chat.

Filesystem Configuration

The list of Redox recipes to be built is read from the filesystem configuration file, which is specified in .config or mk/ If your recipe is not being included in the build, verify if you have set the CONFIG_NAME or FILESYSTEM_CONFIG in the .config file.


Each recipe source is downloaded using git or curl, according to the [source] section of the recipe.toml file. Source is placed at cookbook/recipes/recipe-name/source.

(Some recipes still use the old format, they need to be converted to TOML)

If you are doing work on a recipe, you may want to comment out the [source] section of the recipe. To discard your changes to the source for a recipe, or to update to the latest version, uncomment the [source] section of the recipe, and use make uc.recipe-name in the recipe directory to remove both the source and any compiled code.

After all recipes are fetched, a tag file is created as build/$ARCH/$CONFIG_NAME/fetch.tag, e.g. build/x86_64/desktop/fetch.tag. If this file is present, fetching is skipped. You can remove it manually, or use make rebuild, if you want to force refetching.


Each recipe is built according to the recipe.toml file. The recipe binaries or library objects are placed in the target directory, in a subdirectory named based on the CPU architecture. These tasks are done by various Redox-specific shell scripts and commands, including, and Cargo. These commands make assumptions about $PATH and $PWD, so they might not work if you are using them outside the build process.

If you have a problem with a recipe you are building, try the make c.recipe-name command. A common problem when building on unsupported systems is that certain recipes will fail to build due to missing dependencies. Try using the Podman Build or manually installing the recipe dependencies.

After all recipes are cooked, a tag file is created as build/$ARCH/$CONFIG_NAME/repo.tag. If this file is present, cooking is skipped. You can remove it manually, or use make rebuild, which will force refetching and rebuilding.

Create the Image with FUSE

To build the final Redox image, redox_installer uses FUSE, creating a virtual filesystem and copying the recipe packages into it. This is done outside of Podman, even if you are using Podman Build.

On some Linux distributions, FUSE may not be permitted for some users, or might not install it correctly. Investigate whether you can address your FUSE issues, or join the chat if you need advice.

Solving Compilation Problems

  • Verify your Rust version (run make env and cargo --version, then exit), make sure you have the latest version of Rust nightly!.

    • is recommended for managing Rust versions. If you already have it, run rustup.
  • Verify if your make and nasm are up-to-date.

  • Verify if the build system is using the latest commit by running the git branch -v command.

  • Verify if the submodules are using the latest pinned commit, to do this run:

cd submodule-name
git branch -v
  • Verify if the recipe source is using the latest commit of the default branch, to do this run:
cd cookbook/recipes/some-category/recipe-name/source
git branch -v
  • Run make clean pull fetch to remove all your compiled binaries and update all sources.
  • Sometimes there are merge requests that briefly break the build, so check the Chat if anyone else is experiencing your problems.
  • Sometimes both the source and the binary of some recipe is wrong, run make ucr.recipe-name and verify if it fix the problem.

Environment Leakage

Environment leakage is when some program or library is not fully cross-compiled to Redox, thus its dependency chain has Linux references that don't work on Redox.

It usually happens when the program or library get objects from outside the Redox build system PATH.

  • The Redox build system PATH only read at /usr/bin and /bin to use the host system build tools
  • The program build system must use the host system build tools and the Cookbook recipe dependencies, not the host system libraries.
  • The most common way to detect this is to install the *-dev dependency package equivalent to the program recipe dependency, for example:

The program named "my-program" needs to use the OpenSSL library, thus you add the openssl recipe on the recipe.toml of the program, but the program don't detect the OpenSSL source code.

Then you install the libssl-dev package on your Ubuntu system and rebuild the program with the make command, then it finish the build process successfully.

But when you try to open the executable of the program inside of Redox, it doesn't work. Because it contain Linux references.

To fix this problem you need to find where the program build system get the OpenSSL source code and patch it with ${COOKBOOK_SYSROOT} environment variable (where the openssl recipe contents were copied)

Update Your Build System

Sometimes your build system can be outdated because you forgot to run make pull before other commands, read this section to learn the complete way to update the build system.

In case of backwards-incompatible or relibc changes, you need to use the make clean all command to wipe your binaries and build them again, if it doesn't work you need to download a new copy of the build system by running the script or using this command:

git clone --origin upstream --recursive

After that, run:

cd redox
make all

Update Your Branch

If you are doing local changes on the build system, probably you left your branch active on the folder (instead of master branch).

New branches don't sync automatically with master, thus if the master branch receive new commits, you wouldn't use them because your branch is outdated.

To fix this, run:

git checkout master
git pull
git checkout your-branch
git merge master


git checkout master
git pull
git merge your-branch master

If you want an anonymous merge, read this.

Update relibc

An outdated relibc copy can contain bugs (already fixed on recent versions) or missing APIs, read this section to learn how to update it.

Update crates

Sometimes a Rust program use an old crate version lacking Redox support, read this section to learn how to update them.

Verify the dependency tree

Some crates take a long time to do a new release (years in some cases), thus these releases will hold old versions of other crates, versions where the Redox support is not available (causing errors during the program compilation).

The redox_syscall crate is the most affected by this, some crates hold a very old version of it and will require patches (cargo update -p alone doesn't work).

To identify which crates are using old versions of Redox crates you will need to verify the dependency tree of the program, inside the program source directory, run:

cargo tree --target=x86_64-unknown-redox

This command will draw the dependency tree and you will need to find the crate name on the tree.

If you don't want to find it, you can use the grep tool with a pipe to see all crate versions used in the tree, sadly grep don't preserve the tree hierarchy, thus it's only useful to see versions and if some patched crate works (if the patched crate works all crate matches will report the most recent version).

To do this, run:

cargo tree --target=x86_64-unknown-redox | grep crate-name

Debug Methods

  • Use the dmesg command to read the kernel and user-space daemons log.

  • You can start the QEMU with the make qemu vga=no command to easily copy the terminal text.

  • Use the following command for advanced logging:

make some-command 2>&1 | tee file-name.log
  • You can write to the debug: scheme, which will output on the console, but you must be root. This is useful if you are debugging an app where you need to use Orbital but still want to capture messages.

  • Currently, the build system strips function names and other symbols from programs, as support for symbols is not implemented on Redox.


You will see the available debug methods for recipes on this section.

  • If you change the recipe build mode (release to debug or the opposite) while debugging, don't forget to rebuild with make cr.recipe-name because the build system may not detect the changes.


Rust programs can carry assertions, checking and symbols, but they are disabled by default.

  • COOKBOOK_DEBUG - This environment variable will build the Rust program with assertions, checking and symbols.
  • COOKBOOK_NOSTRIP - This environment variable will package the recipe with symbols.

(Debugging with symbols inside of Redox is not supported yet)

To enable them you can use these commands or scripts:

  • Enable the COOKBOOK_DEBUG environment variable for one command and build a recipe:
COOKBOOK_DEBUG=true make r.recipe-name
  • Enable the COOKBOOK_DEBUG environment variable for multiple commands and build a recipe:
export COOKBOOK_DEBUG=true
make r.recipe-name
  • Enable the COOKBOOK_DEBUG and COOKBOOK_NOSTRIP environment variables for one command and build a recipe:
COOKBOOK_DEBUG=true COOKBOOK_NOSTRIP=true make r.recipe-name
  • Enable the COOKBOOK_DEBUG and COOKBOOK_NOSTRIP environment variables for multiple commands and build a recipe:
export COOKBOOK_DEBUG=true
make r.recipe-name
  • Enable the COOKBOOK_DEBUG environment variable inside the recipe.toml:
template = "custom"
script = """
  • Enable the COOKBOOK_DEBUG and COOKBOOK_NOSTRIP environment variables inside the recipe.toml:
template = "custom"
script = """
  • Backtrace

A backtrace helps you to detect bugs that happen with not expected input parameters, you can trace back through the callers to see where the bad data is coming from.

You can see how to use it below:

  • Start QEMU with logging:
make qemu 2>&1 | tee file-name.log
  • Enable this environment variable globally (on Redox):
export RUST_BACKTRACE=full
  • Run the program and repeat the bug (capturing a backtrace in the log file)

  • Close QEMU

  • Open the log file, copy the backtrace and paste in an empty text file

  • Run the script in the redox directory (on Linux):

scripts/ -r recipe-name -b your-backtrace.txt

It will print the file and line number for each entry in the backtrace.

(This is the most simple example command, use the -h option of the script to see more combinations)

Kill A Frozen Redox VM

Sometimes Redox can freeze or rarely get a kernel panic, to kill the QEMU process run this command:

pkill qemu-system

Kernel Panic

A kernel panic is when some bug avoid the safe execution of the kernel code, thus the system needs to be restarted to avoid data corruption.

We use the following kernel panic message format:

KERNEL PANIC: panicked at some-path/
the panic description goes here
  • You can use the following command to search it in a big log:
grep -nw "KERNEL PANIC" --include "file-name.log"


If you get a kernel panic in QEMU, copy the terminal text or capture a screenshot and send to us on Matrix or create an issue on GitLab.

Real Hardware

If you get a kernel panic in real hardware, capture a photo and send to us on Matrix or create an issue on GitLab.