GIT CLONE --branch <tag_name> results in panic #1571

rrjjvv · 2022-01-14T08:25:06Z

Short preface: even though the argument key is --branch, the docs saying that the argument is <git-ref> had left me hopeful that it wasn't restricted to branches. My first try at providing a commit SHA didn't work. I don't recall the exact failure. That was on an older version, and upon reading the "if you have no choice" from https://docs.earthly.dev/best-practices#git-clone-vs-run-git-clone, I went with that approach.

I recently had a separate need to clone from a tag. Figuring I might have some luck getting earthly to use a tag vs. SHA, I tried again (with a version newer than my previous attempt). It fails with panic interface conversion: interface {} is syscall.WaitStatus, not unix.WaitStatus. When searching for existing reports, I found #1211 . The two comments suggest that both commit SHAs and tags should work. While commits and tags might technically be undocumented/unsupported behavior, the fact that tags failed with a panic (vs. validation error) is why I decided to report.

To reproduce:

$ earthly -v
earthly version v0.6.2 linux/amd64; Debian testing

Earthfile:

FROM alpine

tag:
    # What I originally hoped would work in my scenario
    GIT CLONE --branch v2.30.0 https://git.kernel.org/pub/scm/git/git.git tdir

commit:
    # But I would be happy with this (the tag's SHA), which is implied *should* work in #1211 
    GIT CLONE --branch 71ca53e8125e36efbda17293c50027d31681a41f https://git.kernel.org/pub/scm/git/git.git cdir

signed:
    # kind of works... the SHA for the "signed" tag
    GIT CLONE --branch 2d9685d47a7e516281aa093bf0cddc8aafa72448 https://git.kernel.org/pub/scm/git/git.git sdir

Expectation (hope):

$ earthly prune --reset && earthly +tag
<exit 0 and successful clone>

Actual:

$ earthly prune --reset && earthly +tag 
           buildkitd | Restarting buildkit daemon with reset command...
           buildkitd | ... Done. Future runs will be faster.

 1. Init 🚀
————————————————————————————————————————————————————————————————————————————————

           buildkitd | Found buildkit daemon as docker container (earthly-buildkitd)


 2. Build 🔧
————————————————————————————————————————————————————————————————————————————————

              alpine | --> Load metadata linux/amd64
                +tag | --> GIT CLONE (--branch v2.30.0) https://git.kernel.org/pub/scm/git/git.git
               +base | --> FROM alpine
               +base | [██████████] 100% resolve docker.io/library/alpine@sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
                +tag | hint: Using 'master' as the name for the initial branch. This default branch name
                +tag | hint: is subject to change. To configure the initial branch name to use in all
                +tag | hint: of your new repositories, which will suppress this warning, call:
                +tag | hint: 
                +tag | hint:    git config --global init.defaultBranch <name>
                +tag | hint: 
                +tag | hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
                +tag | hint: 'development'. The just-created branch can be renamed via this command:
                +tag | hint: 
                +tag | hint:    git branch -m <name>
                +tag | Initialized empty Git repository in /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/1/fs/
               +base | [██████████] 100% sha256:59bf1c3509f33515622619af21ed55bbe26d24913cedbca106468a5fb37a50c3
               +base | [██████████] 100% extracting sha256:59bf1c3509f33515622619af21ed55bbe26d24913cedbca106468a5fb37a50c3
                +tag | 2d9685d47a7e516281aa093bf0cddc8aafa72448 refs/tags/v2.30.0
                +tag | From https://git.kernel.org/pub/scm/git/git
                +tag |  * [new tag]         v2.30.0    -> v2.30.0
                +tag | hint: Using 'master' as the name for the initial branch. This default branch name
                +tag | hint: is subject to change. To configure the initial branch name to use in all
                +tag | hint: of your new repositories, which will suppress this warning, call:
                +tag | hint: 
                +tag | hint:    git config --global init.defaultBranch <name>
                +tag | hint: 
                +tag | hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
                +tag | hint: 'development'. The just-created branch can be renamed via this command:
                +tag | hint: 
                +tag | hint:    git branch -m <name>
                +tag | Initialized empty Git repository in /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/3/fs/.git/
                +tag | error: cannot update ref 'refs/heads/v2.30.0': trying to write non-commit object 2d9685d47a7e516281aa093bf0cddc8aafa72448 to branch 'refs/heads/v2.30.0'
                +tag | From /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/1/fs
                +tag |  ! [new tag]         v2.30.0    -> v2.30.0  (unable to update local ref)
                +tag |  * [new tag]         v2.30.0    -> v2.30.0
                +tag | panic: interface conversion: interface {} is syscall.WaitStatus, not unix.WaitStatus

                +tag | goroutine 1 [running]:
                +tag | github.com/moby/buildkit/source/git.gitMain()
                +tag |  /src/source/git/gitsource_unix.go:65 +0x27d
                +tag | github.com/docker/docker/pkg/reexec.Init(...)
                +tag |  /src/vendor/github.com/docker/docker/pkg/reexec/reexec.go:26
                +tag | main.init.0()
                +tag |  /src/cmd/buildkitd/main.go:77 +0xf6
                +tag | WARN: (GIT CLONE (--branch v2.30.0) https://git.kernel.org/pub/scm/git/git.git) exit status 2
Error: build target: build main: bkClient.Build: failed to solve: exit status 2

Note 1: the --prune reset is necessary above (and below) to reliably reproduce these; if I understand correctly, GIT CLONE is a "source", thus exempt from the simpler --no-cache mechanisms.

Note 2: the current docs show usage as --branch <git-ref>, though #1211 showed --branch=<commit>; I tried my experiments with both variations and got the same results

My TL;DR; summary/interpretation/observations:

un-cached attempts to clone via commit SHA or tag name panics and fails
un-cached cloning via SHA of a signed tag still panics, but eventually results in a success
earthly sees a tag name as equivalent to a signed tag SHA, so cloning via commit SHA does work (under proper caching scenarios)
earthly does not see the same equivalence with regular tags

What does work (kind of), which I discovered on accident, is

$ earthly prune --reset && earthly +signed  && earthly +tag
           buildkitd | Restarting buildkit daemon with reset command...
           buildkitd | ... Done. Future runs will be faster.

<snip>
              alpine | --> Load metadata linux/amd64
             +signed | --> GIT CLONE (--branch 2d9685d47a7e516281aa093bf0cddc8aafa72448) https://git.kernel.org/pub/scm/git/git.git
               +base | --> FROM alpine
               +base | [██████████] 100% resolve docker.io/library/alpine@sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
<snip>
             +signed | hint:    git branch -m <name>
             +signed | Initialized empty Git repository in /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/1/fs/
             +signed | fatal: Not a valid object name 2d9685d47a7e516281aa093bf0cddc8aafa72448^{commit}
             +signed | panic: interface conversion: interface {} is syscall.WaitStatus, not unix.WaitStatus

             +signed | goroutine 1 [running]:
             +signed | github.com/moby/buildkit/source/git.gitMain()
             +signed |  /src/source/git/gitsource_unix.go:65 +0x27d
             +signed | github.com/docker/docker/pkg/reexec.Init(...)
             +signed |  /src/vendor/github.com/docker/docker/pkg/reexec/reexec.go:26
             +signed | main.init.0()
             +signed |  /src/cmd/buildkitd/main.go:77 +0xf6
               +base | [██████████] 100% sha256:59bf1c3509f33515622619af21ed55bbe26d24913cedbca106468a5fb37a50c3
               +base | [██████████] 100% extracting sha256:59bf1c3509f33515622619af21ed55bbe26d24913cedbca106468a5fb37a50c3
             ongoing | +signed (1 minute ago)
             +signed | From https://git.kernel.org/pub/scm/git/git
             +signed |  * [new branch]            main       -> origin/main
             +signed |  * [new branch]            maint      -> origin/maint
             +signed |  * [new branch]            master     -> origin/master
             +signed |  * [new branch]            next       -> origin/next
             +signed |  * [new branch]            seen       -> origin/seen
             +signed |  * [new branch]            todo       -> origin/todo
             +signed |  * [new tag]               v2.34.1    -> v2.34.1
             +signed |  * [new tag]               gitgui-0.10.0    -> gitgui-0.10.0
<snip many, many, many tags>
             +signed | HEAD is now at 71ca53e Git 2.30
             +signed | Submodule 'sha1collisiondetection' (https://github.com/cr-marcstevens/sha1collisiondetection.git) registered for path 'sha1collisiondetection'
             +signed | Cloning into '/tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/3/fs/sha1collisiondetection'...
             +signed | From https://github.com/cr-marcstevens/sha1collisiondetection
             +signed |  * branch            855827c583bc30645ba427885caa40c5b81764d2 -> FETCH_HEAD
             +signed | Submodule path 'sha1collisiondetection': checked out '855827c583bc30645ba427885caa40c5b81764d2'
             +signed | --> COPY GIT CLONE (--branch 2d9685d47a7e516281aa093bf0cddc8aafa72448) https://git.kernel.org/pub/scm/git/git.git TO sdir
              output | --> exporting outputs

<snip>
========================== 🌍 Earthly Build  ✅ SUCCESS ==========================
<snip>
 2. Build 🔧
————————————————————————————————————————————————————————————————————————————————

              alpine | --> Load metadata linux/amd64
                +tag | --> GIT CLONE (--branch v2.30.0) https://git.kernel.org/pub/scm/git/git.git
               +base | --> FROM alpine
               +base | [██████████] 100% resolve docker.io/library/alpine@sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
                +tag | 2d9685d47a7e516281aa093bf0cddc8aafa72448 refs/tags/v2.30.0
                +tag | --> COPY GIT CLONE (--branch v2.30.0) https://git.kernel.org/pub/scm/git/git.git TO tdir
              output | --> exporting outputs
<snip>

========================== 🌍 Earthly Build  ✅ SUCCESS ==========================

Notice that it also paniced, with the exact same trace. But it appears that there's a hidden retry/fallback mechanism, which results in a (very long) non-shallow clone, and ultimately succeeds. At that point, the clone of the tag succeeds (when maintaining the cache), presumable due to the first-class citizenship of GIT CLONE and noticing that the signed tag SHA and the tag name are "the same".

But:, with a regular tag:

$ earthly prune --reset && earthly +commit  && earthly +tag
           buildkitd | Restarting buildkit daemon with reset command...
           buildkitd | ... Done. Future runs will be faster.

 1. Init 🚀
————————————————————————————————————————————————————————————————————————————————

           buildkitd | Found buildkit daemon as docker container (earthly-buildkitd)


 2. Build 🔧
————————————————————————————————————————————————————————————————————————————————

              alpine | --> Load metadata linux/amd64
             +commit | --> GIT CLONE (--branch 71ca53e8125e36efbda17293c50027d31681a41f) https://git.kernel.org/pub/scm/git/git.git
               +base | --> FROM alpine
               +base | [██████████] 100% resolve docker.io/library/alpine@sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
<snip>
             +commit | Initialized empty Git repository in /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/1/fs/
             +commit | fatal: Not a valid object name 71ca53e8125e36efbda17293c50027d31681a41f^{commit}
             +commit | panic: interface conversion: interface {} is syscall.WaitStatus, not unix.WaitStatus

             +commit | goroutine 1 [running]:
             +commit | github.com/moby/buildkit/source/git.gitMain()
             +commit |  /src/source/git/gitsource_unix.go:65 +0x27d
             +commit | github.com/docker/docker/pkg/reexec.Init(...)
             +commit |  /src/vendor/github.com/docker/docker/pkg/reexec/reexec.go:26
             +commit | main.init.0()
             +commit |  /src/cmd/buildkitd/main.go:77 +0xf6
               +base | [██████████] 100% sha256:59bf1c3509f33515622619af21ed55bbe26d24913cedbca106468a5fb37a50c3
               +base | [██████████] 100% extracting sha256:59bf1c3509f33515622619af21ed55bbe26d24913cedbca106468a5fb37a50c3
             ongoing | +commit (1 minute ago)
             +commit | From https://git.kernel.org/pub/scm/git/git
             +commit |  * [new branch]            main       -> origin/main
             +commit |  * [new branch]            maint      -> origin/maint
             +commit |  * [new branch]            master     -> origin/master
             +commit |  * [new branch]            next       -> origin/next
             +commit |  * [new branch]            seen       -> origin/seen
             +commit |  * [new branch]            todo       -> origin/todo
             +commit |  * [new tag]               v2.34.1    -> v2.34.1
             +commit |  * [new tag]               gitgui-0.10.0    -> gitgui-0.10.0
<snip many, many tags>
             +commit | HEAD is now at 71ca53e Git 2.30
             +commit | Submodule 'sha1collisiondetection' (https://github.com/cr-marcstevens/sha1collisiondetection.git) registered for path 'sha1collisiondetection'
             +commit | Cloning into '/tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/3/fs/sha1collisiondetection'...
             +commit | From https://github.com/cr-marcstevens/sha1collisiondetection
             +commit |  * branch            855827c583bc30645ba427885caa40c5b81764d2 -> FETCH_HEAD
             +commit | Submodule path 'sha1collisiondetection': checked out '855827c583bc30645ba427885caa40c5b81764d2'
             +commit | --> COPY GIT CLONE (--branch 71ca53e8125e36efbda17293c50027d31681a41f) https://git.kernel.org/pub/scm/git/git.git TO cdir
              output | --> exporting outputs


 3. Push ⏫ (disabled)
————————————————————————————————————————————————————————————————————————————————

To enable pushing use

                earthly --push ...



 4. Local Output 🎁
————————————————————————————————————————————————————————————————————————————————



========================== 🌍 Earthly Build  ✅ SUCCESS ==========================


 1. Init 🚀
————————————————————————————————————————————————————————————————————————————————

           buildkitd | Found buildkit daemon as docker container (earthly-buildkitd)


 2. Build 🔧
————————————————————————————————————————————————————————————————————————————————

              alpine | --> Load metadata linux/amd64
                +tag | --> GIT CLONE (--branch v2.30.0) https://git.kernel.org/pub/scm/git/git.git
               +base | --> FROM alpine
               +base | [██████████] 100% resolve docker.io/library/alpine@sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
                +tag | 2d9685d47a7e516281aa093bf0cddc8aafa72448 refs/tags/v2.30.0
<snip>
                +tag | Initialized empty Git repository in /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/5/fs/.git/
                +tag | error: cannot update ref 'refs/heads/v2.30.0': trying to write non-commit object 2d9685d47a7e516281aa093bf0cddc8aafa72448 to branch 'refs/heads/v2.30.0'
                +tag | From /tmp/earthly/buildkit/runc-overlayfs/snapshots/snapshots/1/fs
                +tag |  ! [new tag]         v2.30.0    -> v2.30.0  (unable to update local ref)
                +tag |  * [new tag]         v2.30.0    -> v2.30.0
                +tag | panic: interface conversion: interface {} is syscall.WaitStatus, not unix.WaitStatus

                +tag | goroutine 1 [running]:
                +tag | github.com/moby/buildkit/source/git.gitMain()
                +tag |  /src/source/git/gitsource_unix.go:65 +0x27d
                +tag | github.com/docker/docker/pkg/reexec.Init(...)
                +tag |  /src/vendor/github.com/docker/docker/pkg/reexec/reexec.go:26
                +tag | main.init.0()
                +tag |  /src/cmd/buildkitd/main.go:77 +0xf6
                +tag | WARN: (GIT CLONE (--branch v2.30.0) https://git.kernel.org/pub/scm/git/git.git) exit status 2
Error: build target: build main: bkClient.Build: failed to solve: exit status 2

I know there's some irony in my report about GIT CLONE being around cloning git's source, but the need is legitimate.)

The text was updated successfully, but these errors were encountered:

alexcb · 2022-01-19T19:54:39Z

Thanks for the great bug report; it turns out buildkit doesn't currently support this. I opened up moby/buildkit#2570 to fix that.

rrjjvv · 2022-02-10T01:40:41Z

I just downloaded the newest version with this change, and it works beautifully. Much appreciated!

vladaionescu added the type:bug Something isn't working label Jan 14, 2022

vladaionescu assigned alexcb Jan 14, 2022

alexcb closed this as completed Feb 10, 2022

rrjjvv mentioned this issue Mar 19, 2022

"Auto" protocol behavior for SSH-based git operations undesirable in some network-restricted environments #1758

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GIT CLONE --branch <tag_name> results in panic #1571

GIT CLONE --branch <tag_name> results in panic #1571

rrjjvv commented Jan 14, 2022

alexcb commented Jan 19, 2022

rrjjvv commented Feb 10, 2022

GIT CLONE --branch <tag_name> results in panic #1571

GIT CLONE --branch <tag_name> results in panic #1571

Comments

rrjjvv commented Jan 14, 2022

alexcb commented Jan 19, 2022

rrjjvv commented Feb 10, 2022