BinaryBuilder sandbox No space left on device

Tooling
1

Trying to build a binary with BinaryBuilder fails with “No space left on device”:

sandbox:${WORKSPACE}/srcdir/Slint.jl/deps/SlintWrapper # df -h
Filesystem                Size      Used Available Use% Mounted on
overlay                   1.0G      1.0G         0 100% /
df: /opt/x86_64-linux-musl/nonce: No such file or directory
df: /opt/x86_64-linux-musl/GCCBootstrap-5.2.0: No such file or directory
df: /opt/x86_64-linux-musl/PlatformSupport-2025.8.13: No such file or directory
df: /opt/x86_64-linux-musl/RustToolchain-1.91.0-x86_64-linux-musl): No such file or directory
df: /opt/x86_64-linux-musl/RustToolchain-1.91.0-x86_64-linux-gnu): No such file or directory
df: /opt/x86_64-linux-musl/RustBase-1.91.0: No such file or directory
df: /opt/x86_64-linux-musl/LLVMBootstrap-18.1.7: No such file or directory
df: /opt/x86_64-linux-gnu/GCCBootstrap-5.2.0: No such file or directory
df: /opt/x86_64-linux-gnu/PlatformSupport-2025.8.13: No such file or directory
overlay                   1.0G      1.0G         0 100% /opt/x86_64-linux-gnu
overlay                   1.0G      1.0G         0 100% /opt/x86_64-linux-musl
udev                      7.8G         0      7.8G   0% /dev/null
udev                      7.8G         0      7.8G   0% /dev/tty
udev                      7.8G         0      7.8G   0% /dev/urandom
/dev/vda4               384.3G    103.6G    261.1G  28% /etc/resolv.conf
/dev/vda4               384.3G    103.6G    261.1G  28% /opt/toolchains
/dev/vda4               384.3G    103.6G    261.1G  28% /opt/bin
/dev/vda4               384.3G    103.6G    261.1G  28% /meta
/dev/vda4               384.3G    103.6G    261.1G  28% /workspace
overlay                 384.3G    103.6G    261.1G  28% /workspace/srcdir

What I found, like
mount -t tmpfs -o size=12G tmpfs /workspace/srcdir
seems not to apply.

What can I do?

2

That’s not very specific, is it? What’s the partition where you don’t have more space? For what is worth, /tmp is mounted on a tiny 1 GB, that’s easy to fill out, but /workspace/srcdir should have access to your entire disk space.

Summary: find what’s writing where, if possible direct it to partitions where you have plenty of space. Temporary directories can be changed by setting the TMPDIR environment variable (that’s a general Unix thing)

3

I provided the output of df -h inside the sandbox. So that’s most specific I can be with my knowledge about this.

4

You didn’t show the error message, which should hopefully tell you where the file is being attempted to be written to.

5

This is the error:

warning: build failed, waiting for other jobs to finish...
error: failed to write /tmp/rustczDZ2xr/lib.rmeta: No space left on device (os error 28)

error: could not compile `jiff` (lib) due to 1 previous error
error: failed to write /tmp/rustcNcVkJj/lib.rmeta: No space left on device (os error 28)

error: could not compile `i-slint-backend-winit` (lib) due to 1 previous error
error: failed to write /tmp/rustc2qVfV6/lib.rmeta: No space left on device (os error 28)

error: could not compile `slint-interpreter` (lib) due to 1 previous error

It is /tmp.

So I am going to use TMPDIR with /workspace/srcdir/tmp and let you know, if this resolves the problem.