dev: fix cross builds running in git worktrees

Beforehand, running a cross build inside a git worktree
would always fail. This PR adds code to also mount the
main git repo into docker when in a git worktree, so that
running cross builds will succeed.

Fixes: cockroachdb#110735
Release note: None

build/bazelutil/stamp.sh

@@ -66,7 +66,11 @@ else
     shift 1
 fi
 
-BUILD_REV=$(git describe --match="" --always --abbrev=40 --dirty)
+BUILD_REV=$(git describe --match="" --always --abbrev=40)
+if [[ -n "$(git status -s --ignore-submodules --untracked-files=no)" ]]; then
+    BUILD_REV=$BUILD_REV-dirty
+fi
+
 BUILD_UTCTIME=$(date -u '+%Y/%m/%d %H:%M:%S')
 
 

pkg/cmd/dev/builder.go

@@ -124,6 +124,19 @@ func (d *dev) getDockerRunArgs(
 	} else {
 		args = append(args, "-i")
 	}
+	gitDir, err := d.exec.CommandContextSilent(ctx, "git", "rev-parse", "--git-dir")
+	if err != nil {
+		return nil, err
+	}
+	gitCommonDir, err := d.exec.CommandContextSilent(ctx, "git", "rev-parse", "--git-common-dir")
+	if err != nil {
+		return nil, err
+	}
+	// If run from inside a git worktree
+	if string(gitDir) != string(gitCommonDir) {
+		mountPath := strings.TrimSpace(string(gitCommonDir))
+		args = append(args, "-v", mountPath+":"+mountPath)
+	}
 	args = append(args, "-v", workspace+":/cockroach")
 	args = append(args, "--workdir=/cockroach")
 	args = append(args, "-v", filepath.Join(workspace, "build", "bazelutil", "empty.bazelrc")+":/cockroach/.bazelrc.user")

pkg/cmd/dev/testdata/recorderdriven/builder

@@ -5,6 +5,8 @@ id
 bazel info workspace --color=no
 cat crdb-checkout/build/.bazelbuilderversion
 docker volume inspect bzlhome
+git rev-parse --git-dir
+git rev-parse --git-common-dir
 mkdir crdb-checkout/artifacts
 docker run --rm -it -v crdb-checkout:/cockroach --workdir=/cockroach -v crdb-checkout/build/bazelutil/empty.bazelrc:/cockroach/.bazelrc.user -v crdb-checkout/artifacts:/artifacts -v bzlhome:/home/roach:delegated -u 502:502 cockroachdb/bazel:20220328-163955
 
@@ -15,5 +17,7 @@ id
 bazel info workspace --color=no
 cat crdb-checkout/build/.bazelbuilderversion
 docker volume inspect bzlhome
+git rev-parse --git-dir
+git rev-parse --git-common-dir
 mkdir crdb-checkout/artifacts
 docker run --rm -i -v crdb-checkout:/cockroach --workdir=/cockroach -v crdb-checkout/build/bazelutil/empty.bazelrc:/cockroach/.bazelrc.user -v crdb-checkout/artifacts:/artifacts -v bzlhome:/home/roach:delegated -u 502:502 cockroachdb/bazel:20220328-163955 echo hi

pkg/cmd/dev/testdata/recorderdriven/builder.rec

@@ -27,6 +27,12 @@ docker volume inspect bzlhome
     }
 ]
 
+git rev-parse --git-dir
+----
+
+git rev-parse --git-common-dir
+----
+
 mkdir crdb-checkout/artifacts
 ----
 
@@ -62,6 +68,12 @@ docker volume inspect bzlhome
     }
 ]
 
+git rev-parse --git-dir
+----
+
+git rev-parse --git-common-dir
+----
+
 mkdir crdb-checkout/artifacts
 ----