support ImportMap from go list -json' output

[pagran]

Part of #134

typecheck error: C:\Go\src\vendor\golang.org\x\crypto\chacha20\chacha_generic.go:15:2: could not import golang.org/x/crypto/internal/subtle (path not found in listed packages: golang.org/x/crypto/internal/subtle)

I suppose this error appears when the output `go list -json -deps' appears:

	"Imports": [
		"crypto/cipher",
		"encoding/binary",
		"...",
		"vendor/golang.org/x/crypto/internal/subtle",
		"math/bits",
		"runtime"
	],
	"ImportMap": {
		"golang.org/x/crypto/internal/subtle": "vendor/golang.org/x/crypto/internal/subtle". # important line
	},

Full output: https://gist.github.com/pagran/d2da864552406f3667f685baaa6deeac

[mvdan]

Nice catch, I wasn't aware of ImportMap. Adding support for that shouldn't be too difficult, and we should be able to add a vendor.txt with a vendored import to test this.

[pagran]

If this is fixed, most likely, I can fix #134 + increase "buildability" of large projects.

[mvdan]

I first assumed I could reproduce this by just vendoring dependencies, but go list -json -deps would still not include any ImportMap field. So I'm not sure how to minimally reproduce this edge case. I've raised golang/go#42446 upstream to try to actually understand when and why ImportMap shows up.

[mvdan]

OK, I was able to reproduce. The cause was a package vendored in the standard library.

[mvdan]

Alright, I fixed the first issue on our end, but now we're failing due to Binject/debug#17.

[capnspacehook]

The only reason garble uses goobj2's ParseImportcfg function is because Binject/debug#13 isn't fixed right? Seems like the best solution might just be to fix that

[mvdan]

Indeed.