Fails with import errors with modules on Go 1.11

[atombender]

If I have a simple file such as this that refers to an imported package:

package mypackage
import "github.com/jackc/pgx"
// ...

then it fails with:

/Users/alex/.go/pkg/mod/github.com/jackc/pgx@v3.1.0+incompatible/batch.go:6:2: could not import github.com/jackc/pgx/pgproto3 (cannot find package "github.com/jackc/pgx/pgproto3" in any of:
	/usr/local/opt/go/libexec/src/github.com/jackc/pgx/pgproto3 (from $GOROOT)
	/Users/alex/.go/src/github.com/jackc/pgx/pgproto3 (from $GOPATH))

In other words, it's looking for the source in the old location, not in $GOPATH/pkg/mod.

I'm able to reproduce this in a small Go program that uses golang.org/x/tools/go/loader to load files, and I can confirm that it does not work with Go modules. (E.g. see this issue for discussion.) Apparently the golang.org/x/tools/go/loader library has been superceded by golang.org/x/tools/go/packages, which is module-aware.

[atombender]

@evanphx? This is a complete blocker on Go 1.11 with modules.

[atombender]

@evanphx? This is a complete blocker on Go 1.11 with modules.

[mjlangan]

We are seeing similar errors from mockery after trying Go 1.11 with modules

Generating mock for: Adapter in file: mocks/Adapter.go
/Users/michaell/go/src/golang.org/x/crypto/ssh/terminal/util.go:20:2: could not import golang.org/x/sys/unix (cannot find package "golang.org/x/sys/unix" in any of:
    /usr/local/go/src/golang.org/x/sys/unix (from $GOROOT)
    /Users/michaell/go/src/golang.org/x/sys/unix (from $GOPATH))
/Users/michaell/go/pkg/mod/github.com/!sirupsen/logrus@v1.0.6/terminal_bsd.go:6:8: could not import golang.org/x/sys/unix (cannot find package "golang.org/x/sys/unix" in any of:
    /usr/local/go/src/golang.org/x/sys/unix (from $GOROOT)
    /Users/michaell/go/src/golang.org/x/sys/unix (from $GOPATH))
...

go mod vendor does pull these dependencies into the repository's /vendor/ folder, but it appears that mockery doesn't look there for dependencies when generating mocks.

[mjlangan]

We are seeing similar errors from mockery after trying Go 1.11 with modules

Generating mock for: Adapter in file: mocks/Adapter.go
/Users/michaell/go/src/golang.org/x/crypto/ssh/terminal/util.go:20:2: could not import golang.org/x/sys/unix (cannot find package "golang.org/x/sys/unix" in any of:
    /usr/local/go/src/golang.org/x/sys/unix (from $GOROOT)
    /Users/michaell/go/src/golang.org/x/sys/unix (from $GOPATH))
/Users/michaell/go/pkg/mod/github.com/!sirupsen/logrus@v1.0.6/terminal_bsd.go:6:8: could not import golang.org/x/sys/unix (cannot find package "golang.org/x/sys/unix" in any of:
    /usr/local/go/src/golang.org/x/sys/unix (from $GOROOT)
    /Users/michaell/go/src/golang.org/x/sys/unix (from $GOPATH))
...

go mod vendor does pull these dependencies into the repository's /vendor/ folder, but it appears that mockery doesn't look there for dependencies when generating mocks.