[7.7.1] Windows CI builds failing with "expected an absolute Windows path for junction_target" #28406
Description
Originally reported as bazelbuild/continuous-integration#2445, as this seems to be due to an infrastructure change. Please see that issue for more details.
Reporting here in case the proper approach is to update the local_repository implementation.
ERROR: <builtin>: fetching local_repository rule //:rules_scala+:
java.io.IOException: Could not create symlink to repository
"/c/b/bk-windows-8slj/bazel/rules-scala-scala/tmp/test_bzlmod_macros"
(absolute path: "/c/b/bk-windows-8slj/bazel/rules-scala-scala/tmp/test_bzlmod_macros"):
Cannot create junction
(name=C:\tools\msys64\home\b\_bazel_b\jto5y4qq\external\rules_scala+,
target=\c\b\bk-windows-8slj\bazel\rules-scala-scala\tmp\test_bzlmod_macros):
ERROR: src/main/native/windows/file-jni.cc(122):
nativeCreateJunction(\\?\C:\tools\msys64\home\b\_bazel_b\jto5y4qq\external\rules_scala+,
\\?\\c\b\bk-windows-8slj\bazel\rules-scala-scala\tmp\test_bzlmod_macros):
ERROR: src/main/native/windows/file.cc(231):
CreateJunction(\\?\\c\b\bk-windows-8slj\bazel\rules-scala-scala\tmp\test_bzlmod_macros):
expected an absolute Windows path for junction_targetI've only seen this with Bazel 7.7.1 so far. All of the native Windows code in the vicinity of the error path seems quite old, even on master, and local_repository has only changed to add a rctx.watch call.