ICU-20555 Fix Windows build failures with long paths: Use PowerShell when command length exceeds CMD's limit.
diff --git a/icu4c/source/python/icutools/databuilder/renderers/common_exec.py b/icu4c/source/python/icutools/databuilder/renderers/common_exec.py
index 26c4c8a..838b121 100644
--- a/icu4c/source/python/icutools/databuilder/renderers/common_exec.py
+++ b/icu4c/source/python/icutools/databuilder/renderers/common_exec.py
@@ -98,7 +98,7 @@
if platform == "windows":
# Note: this / to \ substitution may be too aggressive?
command_line = command_line.replace("/", "\\")
- returncode = run_shell_command(command_line, verbose)
+ returncode = run_shell_command(command_line, platform, verbose)
if returncode != 0:
return returncode
return 0
@@ -111,23 +111,36 @@
if platform == "windows":
# Note: this / to \ substitution may be too aggressive?
command_line = command_line.replace("/", "\\")
- returncode = run_shell_command(command_line, verbose)
+ returncode = run_shell_command(command_line, platform, verbose)
return returncode
assert False
-def run_shell_command(command_line, verbose):
+def run_shell_command(command_line, platform, verbose):
+ changed_windows_comspec = False
+ # If the command line length on Windows exceeds the absolute maximum that CMD supports (8191), then
+ # we temporarily switch over to use PowerShell for the command, and then switch back to CMD.
+ # We don't want to use PowerShell for everything though, as it tends to be slower.
+ if (platform == "windows") and (len(command_line) > 8190):
+ if verbose:
+ print("Command length exceeds the max length for CMD on Windows, using PowerShell instead.")
+ previous_comspec = os.environ["COMSPEC"]
+ os.environ["COMSPEC"] = 'powershell'
+ changed_windows_comspec = True
if verbose:
print("Running: %s" % command_line)
- return subprocess.call(
+ returncode = subprocess.call(
command_line,
shell = True
)
else:
# Pipe output to /dev/null in quiet mode
with open(os.devnull, "w") as devnull:
- return subprocess.call(
+ returncode = subprocess.call(
command_line,
shell = True,
stdout = devnull,
stderr = devnull
)
+ if changed_windows_comspec:
+ os.environ["COMSPEC"] = previous_comspec
+ return returncode
