This runs much faster than before. This change removes all of the
async status output because all of the compute time is spent inside
go/packages, with no opportunity to update the status.
Adds testdata code to prove it fails when expected.
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Update all script shebangs to use /usr/bin/env interpreter instead of /bin/interpreter
This is required to support systems where bash doesn't reside in /bin (such as NixOS, or the *BSD family) and allow users to specify a different interpreter version through $PATH manipulation.
https://www.cyberciti.biz/tips/finding-bash-perl-python-portably-using-env.html
```release-note
Use /usr/bin/env in all script shebangs to increase portability.
```
Most of the time spent compiling is spent optimizing and linking
binary code. Most errors occur at the syntax or semantic (type) layers.
Go's compiler is importable as a normal package, so we can do fast
syntax and type checking for the 10 platforms we build on.
This currently takes ~6 minutes of CPU time (parallelized).
This makes presubmit cross builds superfluous, since it should catch
most cross-build breaks (generally Unix and 64-bit assumptions).
Example output:
$ time go run test/typecheck/main.go
type-checking: linux/amd64, windows/386, darwin/amd64, linux/arm, linux/386, windows/amd64, linux/arm64, linux/ppc64le, linux/s390x, darwin/386
ERROR(windows/amd64) pkg/proxy/ipvs/proxier.go:1708:27: ENXIO not declared by package unix
ERROR(windows/386) pkg/proxy/ipvs/proxier.go:1708:27: ENXIO not declared by package unix
real 0m45.083s
user 6m15.504s
sys 1m14.000s
