--output_base does not replace user prefix ~

Description of the problem / feature request:

The --output_base option does not seem to replace the user home directory ~ pattern.

Feature requests: what underlying problem are you trying to solve with this feature?

I’d like to specify an --output_base relative to the user home directory.

Bugs: what’s the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Add a path with ~ in your .bazelrc:

$ tail -n 1 .bazelrc 
startup --output_base ~/fromage

Build:

$ bazel build //...

Look is the different directories and observe that the ~ was not replaced:

$ ls ~/fromage
ls: cannot access '/home/guillaume/fromage': No such file or directory

$  ls ./\~/fromage
bazel-remote-logs  bazel-workers  command.log  DO_NOT_BUILD_HERE  execroot  external  install  java.log  java.log.paddle.guillaume.log.java.20210125-170253.13883  javalog.properties  lock  README  server

What operating system are you running Bazel on?

Linux

What’s the output of bazel info release?

$ kazel info release
INFO: Invocation ID: b730d2ac-1af0-4106-842c-754a0b37e740
release 3.3.1- (@non-git)

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

I picked the one from nixpkgs.

Please note that it works with a few other options, such as --disk_cache.

[aranguyen]

@guibou bazelrc does not have support for shell expansion. We unfortunately do not have plan to prioritize this any time soon. I’m marking this as duplicate of https://github.com/bazelbuild/bazel/issues/10904. Please feel free to share your thoughts in the doc mentioned in https://github.com/bazelbuild/bazel/issues/10904#issuecomment-1212144290

[brentleyjones]

https://github.com/bazelbuild/bazel/pull/15417 is an example of changing a flag to accept tildes. I think we can do that for this flag, and others, as well.