tree 417df26a5e25a53a5cf3e0e4c5f6c4f730922091
parent 61d20a558f03a7cb0e2ebc9002c8be7db94cf74e
author Asim Shankar <ashankar@google.com> 1408208943 -0700
committer Asim Shankar <ashankar@google.com> 1408208943 -0700

veyron/tools/build: Support for cgo

The "C" package is a pseudo-package and thus attempts to import it will fail.
The lack of special handling for the C pseudo-package was causing tests on
OS X to fail with:

--- FAIL: TestBuildClient (0.03s)
        impl_test.go:66: Import("C","",0) failed: cannot find package "C" in any of:
                        /Users/ashankar/veyron/environment/go/src/pkg/C (from $GOROOT)
                        /Users/ashankar/veyron/third_party/go/src/C (from $GOPATH)
                        /Users/ashankar/veyron/tools/go/src/C
                        /Users/ashankar/veyron/veyron/go/src/C
                        /Users/ashankar/veyron/environment/golib/src/C

since after https://veyron-review.googlesource.com/#/c/3698/
the package being built in TestBuildClient has a dependency on the C pseudo-package
on OS X
(veyron/runtimes/google/rt depends on C)

The test was passing on linux because the C dependency doesn't exist there.
But builds of real packages which require "cgo" would have failed.

Change-Id: I34ef496e2e77da568318652a4a5dcda8f7c88b67