Also consistently deduplicate Env entries, mainly to reduce confusion
when reading logs.
This change is probably larger than what is strictly needed to fix the
issue, but it seemed simpler than trying to figure out which of the
many calls to exec.Command in the module are actually relevant.
(It also provides some useful case studies for possible additions to
the Go standard library.)
For golang/go#33598
Change-Id: Ia2bce4549e4a71b56fb497e3df093f79fbcf7f29
Reviewed-on: https://go-review.googlesource.com/c/build/+/353549
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Bryan C. Mills