--repo_env causes fetch/query thrashing

[laurentlb]

@laurentlb it is the bazel build --repo_env that causes the fetch/query thrashing. Both bazel query and bazel fetch do not have a --repo_env flag, but its presence in bazel build causes bazel to consider the fetch and build steps to be different, hence the thrashing.

Originally posted by @TheButlah in #10961 (comment)

[TheButlah]

For some additional context on why this is important in my particular use case - we rely on bazel query for several scripts/systems to interoperate with bazel, so it gets invoked about as frequently as bazel build. We also have set the default C/C++ compiler via a build --repo_env=CXX=clang++-11 --repo_env=CC=clang-11 in our .bazelrc file. This means that we get consistent re-fetching of external workspaces. Suffice to say, its generating quite a bit of tooling pain for our team.

Note that this seems to occur in at least 3.2.0 and 3.4.1

[laurentlb]

If --repo_env forces a re-evaluation, the flag should be available for bazel query too.

[TheButlah]

Any movement here?

[liuliu]

One way I worked around this is to have a dedicated output_base when running bazel query. It seems to be the solution done by the VSCode Bazel plugin as well.

[pcjanzen]

A no-good, very bad thing that you absolutely should not do under any circumstances because it is undocumented and unsupported and could stop working at any moment is to put

common --client_env=FOO=BAR

into your .bazelrc.

[bjacklyn]

@chancila -- I believe your repo_env change may also fix this issue
c2bdd03

[chancila]

yea I think there's a bunch of duplicate issues around this #12689

[fmeum]

@sgowroji Can be closed based on #11943 (comment).

[sgowroji]

We are closing this issue w.r.t the above #11943 (comment). Thanks!