buf generate: fails on symlinks without proper permissions

[adambabik]

I tried to run buf generate with one dependency:

deps:
  - buf.build/beta/googleapis

and a broken symlink in the root project directory.

The command failed on resolving the symlink:

buf generate
buf: downloading buf.build/beta/googleapis:1dc4674e3cb949b388204fa2dc321be7
lstat /root/.cache: permission denied

Where a symlink pointed at: /root/.cache/bazel/path/to/file.

[johanbrandhorst]

I saw this error too, I think it may have something to do with how the grpc-gateway uses a docker container to generate the files. buf will look for $BUF_CACHE_DIR and $XDG_CACHE_HOME or otherwise fall back to $HOME/.cache, so if this error happens, it's likely something to do with the local configuration. See

buf/internal/pkg/app/app_unix.go

Line 70 in 4d19835

func CacheDirPath(envContainer EnvContainer) (string, error) {

and

buf/internal/pkg/app/appname/container.go

Line 82 in 4d19835

c.cacheDirPath = c.getDirPath("CACHE_DIR", app.CacheDirPath)

.

Another note, because running generate inside a container can mess with permissions, you may need to run sudo chown $(whoami): -R . after regenerating files.

[adambabik]

I found this code and tried to use these envs but with no luck (I tried also with CACHE_DIR):

➜ export XDG_CACHE_HOME=$HOME/.cache
➜ echo $XDG_CACHE_HOME 
/home/adamb/.cache
➜ buf generate     
lstat /root/.cache: permission denied

You are right with the docker and permissions being broken but after I fixed it, it's the same error. I can try to dig into the code of buf to find a code path that does not work if it's hard to reproduce. Like I said above, it works like a charm on macOS.

[johanbrandhorst]

I can't reproduce this error locally anymore, but it would be super helpful if you could keep your environment broken and help us debug what's happening here. I'd add some print statements to the code to see why it's choosing that path and rebuild, if you want I can provide the binaries for you to try?

[adambabik]

I talked with @johanbrandhorst on Buf's Slack. We found that the root cause was a broken symlink pointing at a directory to which the current user had no permissions. I updated the description.

[johanbrandhorst]

In the next release we're making the error message around this a bit clearer so the user knows to look at the contents of their repository.

[bufdev]

An updated error message is included in v0.37.1.