Convert MSYS' Linux-like paths to Windows paths in JAX CI.

This is necessary on Windows because some applications such as Bazel/Docker do not understand/handle Linux-like paths that msys uses.

The script first converts all `JAXCI.*DIR` variables containing msys-like paths to Windows paths using cygpath.  Then it sources those variables into the shell environment so that any tools that use those variables can run correctly.

PiperOrigin-RevId: 702533023

ci/utilities/convert_msys_paths_to_win_paths.py

@@ -0,0 +1,80 @@
+# Copyright 2024 The JAX Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""
+Converts MSYS Linux-like paths stored in env variables to Windows paths.
+
+This is necessary on Windows, because some applications do not understand/handle
+Linux-like paths MSYS uses, for example, Bazel.
+"""
+import argparse
+import os
+import subprocess
+
+def msys_to_windows_path(msys_path):
+  """Converts an MSYS path to a Windows path using cygpath.
+
+  Args:
+    msys_path: The MSYS path to convert.
+
+  Returns:
+    The corresponding Windows path.
+  """
+  try:
+    # Use cygpath with the -w flag to convert to Windows format
+    process = subprocess.run(['cygpath', '-w', msys_path], capture_output=True, text=True, check=True)
+    windows_path = process.stdout.strip()
+    return windows_path
+  except FileNotFoundError:
+    print("Error: cygpath not found. Make sure it's in your PATH.")
+    return None
+  except subprocess.CalledProcessError as e:
+    print(f"Error converting path: {e}")
+    return None
+
+def should_convert(var: str,
+                   convert: list[str] | None):
+  """Check the variable name against convert list"""
+  if var in convert:
+    return True
+  else:
+    return False
+
+def main(parsed_args: argparse.Namespace):
+  converted_paths = {}
+
+  for var, value in os.environ.items():
+    if not value or not should_convert(var,
+                                       parsed_args.convert):
+      continue
+    converted_path = msys_to_windows_path(value)
+    converted_paths[var] = converted_path
+
+  var_str = '\n'.join(f'export {k}="{v}"'
+                      for k, v in converted_paths.items())
+  # The string can then be piped into `source`, to re-set the
+  # 'converted' variables.
+  print(var_str)
+
+
+if __name__ == '__main__':
+  parser = argparse.ArgumentParser(description=(
+      'Convert MSYS paths in environment variables to Windows paths.'))
+  parser.add_argument('--convert',
+                      nargs='+',
+                      required=True,
+                      help='Space separated list of environment variables to convert. E.g: --convert env_var1 env_var2')
+  args = parser.parse_args()
+
+  main(args)

ci/utilities/setup_build_environment.sh

@@ -68,4 +68,11 @@ if [[ ! -z ${JAXCI_XLA_GIT_DIR} ]]; then
   echo "and JAXCI_XLA_COMMIT in your environment. Note that the Bazel RBE test"
   echo "commands overrides the XLA repository and thus require a local copy of"
   echo "XLA to run."
+fi
+
+# On Windows, convert MSYS Linux-like paths to Windows paths.
+if [[ $(uname -s) =~ "MSYS_NT" ]]; then
+  echo 'Converting MSYS Linux-like paths to Windows paths (for Bazel, Python, etc.)'
+  # Convert all "JAXCI.*DIR" variables
+  source <(python3 ./ci/utilities/convert_msys_paths_to_win_paths.py --convert $(env | grep "JAXCI.*DIR" | awk -F= '{print $1}'))
 fi