checkErrors is preventing dep ensure from working within dep

[ibrasho]

What dep command did you run?

I tried to dep ensure -v in github.com/golang/dep and got the following output:

$ dep ensure -v
Found 5 errors:

/Users/ibrahim/Code/go/src/github.com/golang/dep/cmd/dep/testdata/harness_tests/ensure/pkg-errors/case2/initial/bar/bar.go:3:51: expected 'package', found 'EOF'
/Users/ibrahim/Code/go/src/github.com/golang/dep/internal/gps/_testdata/src/bad/bad.go:6:43: expected 'package', found 'EOF'
import path github.com/golang/dep/internal/gps/_testdata/src/relimport/dotslash had a local import: "./simple"
import path github.com/golang/dep/internal/gps/_testdata/src/relimport/dotdotslash had a local import: "../github.com/golang/dep/internal/gps"
import path github.com/golang/dep/internal/gps/_testdata/src/relimport/dotdot had a local import: ".."

What did you expect to see?

A normal ensure output.

What did you see instead?

#844 introduced some additional rules to check when projects contain Go files with errors. Applying these rules on dep resulted in this case. 😁

Since dep has some test cases (and test data) with invalid Go files, dep ensure cannot be used in github.com/golang/dep.

cc: @grepory

[ibrasho]

I think it would be great if we add more output before printing Found # errors:. Since it's not really clear what went wrong.

Something like Calculating imported package tree... and Finished calculating imported package tree. if no error occurred?

[sdboyer]

baaaaaarrrgghhhh lol

[sdboyer]

i thought i pieced through those cases, but evidently not. let's get a fast fix in on this one, if we can?

[ibrasho]

I created a PR. That function does the following now:

• If all directories lack Go files, return an error.
• If all directories have build errors, return an error.
• If all directories either lack Go files or has a build error, return an error.
• If some directories are compilable but the tree contains build errors, return a warning with the errors.