Bazel doesn't respect XDG_CACHE_HOME

[ebyrne242]

Description of the bug:

Bazel writes caches, often many megabytes in size to $USER/.cache/bazel on Linux. It's common for users on NFS home dirs to set the XDG_CACHE_HOME environment variable to put their caches on a local disk instead. However, bazel ignores this variable and continues to write to ~/.cache/bazel.

What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

export XDG_CACHE_HOME=/tmp/$USER/bazel

build anything with bazel

bazel still writes output to ~/.cache/bazel

Which operating system are you running Bazel on?

CentOS 7.9

What is the output of bazel info release?

No response

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

$ bazel info release

WARNING: Output base '/data/homes/nfs/home/user/.cache/bazel/_bazel_user/33181acb49c359f0b2bfbb3335eecb1f' is on NFS. This may lead to surprising failures and undetermined behavior.

release 5.3.2

What's the output of git remote get-url origin; git rev-parse master; git rev-parse HEAD ?

No response

Have you found anything relevant by searching the web?

Suggestions that TEST_TMPDIR is the only way to influence the output dir, along with suggestions it should not be used.

Any other information, logs, or outputs that you want to share?

No response

[sgowroji]

Hello @sketch242, Could you please provide an example code to reproduce the above issue. Thanks !

[ebyrne242]

It's not code specific, you can use anything.

$ git clone https://github.com/bazelbuild/examples
Cloning into 'examples'...
remote: Enumerating objects: 1995, done.
remote: Counting objects: 100% (600/600), done.
remote: Compressing objects: 100% (410/410), done.
remote: Total 1995 (delta 219), reused 441 (delta 147), pack-reused 1395
Receiving objects: 100% (1995/1995), 542.98 KiB | 7.87 MiB/s, done.
Resolving deltas: 100% (763/763), done.
$ cd examples/cpp-tutorial/stage1/
$ export $XDG_CACHE_HOME=/data/cache/user
$ readlink -m $HOME
/data/homes/nfs/home/user
$ rm -rf ~/.cache/bazel /data/cache/user/bazel
$ bazel build //main:hello-world
Extracting Bazel installation...
Starting local Bazel server and connecting to it...
INFO: Analyzed target //main:hello-world (37 packages loaded, 163 targets configured).
INFO: Found 1 target...
Target //main:hello-world up-to-date:
  bazel-bin/main/hello-world
INFO: Elapsed time: 6.790s, Critical Path: 0.35s
INFO: 6 processes: 4 internal, 2 processwrapper-sandbox.
INFO: Build completed successfully, 6 total actions
$ ls -ld/data/cache/user/bazel/
ls: cannot access /data/cache/user/bazel/: No such file or directory
$ ls -ld /data/homes/nfs/home/user/.cache/bazel/_bazel_user/8fb73c6900510c4b2c71adc08d4544df
drwxr-xr-x. 6 user users 4096 Dec  7 13:10 /data/homes/nfs/home/user/.cache/bazel/_bazel_user/8fb73c6900510c4b2c71adc08d4544df

[tetromino]

We should fix this.

[tetromino]

... and until this is fixed, as a workaround, you can do bazel --output_user_root=/tmp/$USER/bazel build ... - see https://bazel.build/remote/output-directories#layout

[Wyverald]

@bazel-io fork 7.2.0

[iancha1992]

A fix for this issue has been included in Bazel 7.2.0 RC1. Please test out the release candidate and report any issues as soon as possible.
If you're using Bazelisk, you can point to the latest RC by setting USE_BAZEL_VERSION=7.2.0rc1. Thanks!