Fails silently when custom buildpack fails to download from Git

[callahad]

The logic in buildpack.bash attempts to git ls-remote $url, and falls back to trying to pipe from curl into tar, with arguments based on file extension.

In my case, I was using a buildpack with a GitHub, but ls-remote failed due to a connectivity issue. The following case statement failed to match any extensions, leaving tar_args empty. Which caused tar to fail as tar without one of -Acdrtux is invalid.

[jstr]

I'm seeing this too. build exits with The command '/bin/sh -c /build' returned a non-zero code: 128.

[michaelshobbs]

PRs welcomed

[jstr]

After some investigation I found my issue was actually in heroku-buildpack-multi (https://github.com/drgarcia1986/heroku-buildpack-multi/blob/master/bin/compile#L23). However that package is no longer maintained and is not tracking issues.