rules_nodejs downstream dependency broken at HEAD

[c-parsons]

rules_nodejs is broken on all platforms with:

ERROR: java.io.IOException: Cannot run program "echo BUILD_SCM_VERSION 1.2.3" (in directory "/var/lib/buildkite-agent/builds/buildkite-ubuntu1404-q6xf-1/bazel-downstream-projects/rules_nodejs"): error=2, No such file or directory

Failure log:
https://buildkite.com/bazel/bazel-with-downstream-projects-bazel/builds/201#033578ee-a114-4fbe-be77-9327536634cd

Bisect shows the culprit is commit 073ea09

[laszlocsomor]

Culprit is in
https://github.com/bazelbuild/rules_nodejs/blob/1931156c232a08356dfda02e9c8b0275c2e63c00/tools/bazel.rc#L7

This bazelrc file uses --workspace_status_command incorrectly, specifying a Bash command instead of a path to a binary. Though the documentation says you must use a path, Bazel doesn't verify that so users couldn't have known.

Before 073ea09, Bazel used to run the flag's value through Bash so a raw command worked too, after the commit Bazel executed the flag's value thinking it was a path to a program, and that blew up.

I'll add error checking to Bazel, then probably I have to fix some broken projects in BuildKite, then I'll re-submit 073ea09.

[c-parsons]

Closing, as the original breakage was rolled back.