"command interrupted while computing main repo mapping" without any indication of progress

[lberki]

Description of the bug:

When I build a Fuchsia example project, Bazel@HEAD hangs for a few minutes while Bazel 5.3.0 provides reasonable progress reporting.

--profile indicates that it's repository fetching that's happening during the hang.

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

Following the instructions here while using a Bazel built from HEAD:

https://fuchsia.googlesource.com/sdk-samples/fortune-teller/

essentially:

git clone https://fuchsia.googlesource.com/sdk-samples/fortune-teller
cd fortune-teller
git submodule update --recursive --init
bazel build @fuchsia_sdk//:fuchsia_toolchain_sdk

Then the console output is:

>> bazel build @fuchsia_sdk//:fuchsia_toolchain_sdk
Extracting Bazel installation...
Starting local Bazel server and connecting to it...
# Hangs for >1 minute
^C
Bazel caught interrupt signal; shutting down.

ERROR: command interrupted while computing main repo mapping

This is in constrast with Bazel 5.3.0, which tells me on the console that it's currently busy fetching repositories.

Which operating system are you running Bazel on?

Linux

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.

From commit 8a53266 .

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?

No response

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

No response

[meteorcloudy]

Why is this area-Bzlmod?

[lberki]

AFAIU bzlmod is the only significant user of repo mapping, so mainly by association

[meteorcloudy]

Oh, I see, this is introduced in https://cs.opensource.google/bazel/bazel/+/943e8cfb9970ca86f88ba60c944601573b366db5

[meteorcloudy]

/cc @Wyverald

[lberki]

I'm glad my crystal ball worked well this time :)