cmd/go: unable to "go get" repository with external LFS server (go modules)

[campbellr]

What version of Go are you using (go version)?

$ go version
go version go1.14.3 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/ryancampbell/Library/Caches/go-build"
GOENV="/Users/ryancampbell/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY="github.com/kirasystems/*"
GONOSUMDB="github.com/kirasystems/*"
GOOS="darwin"
GOPATH="/Users/ryancampbell/go"
GOPRIVATE="github.com/kirasystems/*"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.14.3/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.14.3/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/k7/np6wbqs53wvgc5167kfc81yr0000gp/T/go-build056608014=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I have a repository that use Git LFS, with a external LFS server configured via a .lfsconfig file in the root of the repository (docs).

When I attempt to go get a package in this repo in "module-aware mode", it fails with the following error:

$ go get github.com/campbellr/goproject/package
go: downloading github.com/campbellr/goproject v0.0.0-20200618225840-1c974a2e2163
go: downloading github.com/campbellr/goproject/package v0.0.0-20200618225840-1c974a2e2163
go get github.com/campbellr/goproject/package: git -c core.autocrlf=input -c core.eol=lf archive --format=zip --prefix=prefix/ 1c974a2e2163f0097eddb66edd91ebbb725cc3fc -- package in /Users/ryancampbell/go/pkg/mod/cache/vcs/bc6786f5d692de19e81d93e06b7c197cfd764a6b5981aeb750293aad946567ca: exit status 128:
        Downloading package/some-lfs-file.model (9.8 KB)
        Error downloading object: package/some-lfs-file.model (0759275): Smudge error: Error downloading package/some-lfs-file.model (0759275b587490b6e6124f421b9781362517cd1aa2354c4e849f3949adb05f94): [0759275b587490b6e6124f421b9781362517cd1aa2354c4e849f3949adb05f94] Object does not exist on the server: [404] Object does not exist on the server

        Errors logged to /Users/ryancampbell/go/pkg/mod/cache/vcs/bc6786f5d692de19e81d93e06b7c197cfd764a6b5981aeb750293aad946567ca/lfs/logs/20200619T084543.526724.log
        Use `git lfs logs last` to view the log.
        error: external filter 'git-lfs filter-process' failed
        fatal: package/some-lfs-file.model: smudge filter lfs failed

As far as I can tell, the problem seems to be due to the way that go get clones the git repository.

1. git init --bare
2. git remote add origin github.com/campbellr/goproject
3. git fetch
4. git archive thepackage/ directory

Since git archive is running in a bare repository, there is no .lfsconfig, so git-lfs doesn't fetch the objects from the right lfs server and gets a 404.

Note that the same go get will succeed in GOPATH mode (since it just does a normal git clone)

[cagedmantis]

/cc @bcmills @jayconrod @matloob

[jayconrod]

Related #25605, especially this comment.

For posterity: I think that any repositories being built by vgo depend on a Git LFS object during compilation will fail, since those objects will not be checked out, (because the repository is bare). That's a limitation of git-archive(1) and Git LFS, but not vgo.

[campbellr]

tbh, I wasn't sure if this was more appropriate as a git-lfs or git-archive issue rather than a Go issue, but I ended up filing it here because:

1. This is a regression from GOPATH mode go get, which works as expected
2. This is a result of go get cloning the repo in an "unexpected" way. I'm sure there is a good reason for it, but it does seem break assumptions that git-lfs (and possibly other tools?) seems to depend on.

[bcmills]

See also #29987 (also related to LFS).

[bcmills]

See also #38941 (comment) (somehow related to git-lfs smudging).

[pebbe]

This issue is four years old. Why isn't this fixed yet?

[ianlancetaylor]

@pebbe This is open source software and this is not a common case. If you are running into this I would encourage you to send in a patch. See https://go.dev/doc/contribute. Thanks.

[pebbe]

@pebbe This is open source software and this is not a common case. If you are running into this I would encourage you to send in a patch. See https://go.dev/doc/contribute. Thanks.

I don't have the expertise to fix go get.