Workaround an RBE bug where stderr is merged with stdout.

Any code path using exec_result.stderr won't work with RBE due to
a bug where the service returns stderr as stdout.

PiperOrigin-RevId: 295107492
Change-Id: I5738d46f7bb4cc049636a6f6625abc782d2d1e29

third_party/gpus/cuda_configure.bzl

@@ -39,6 +39,7 @@ load(
 )
 load(
     "//third_party/remote_config:common.bzl",
+    "err_out",
     "get_bash_bin",
     "get_cpu_value",
     "get_python_bin",
@@ -273,20 +274,21 @@ def _get_cxx_inc_directories_impl(repository_ctx, cc, lang_is_cpp, tf_sysroot):
         sysroot += ["--sysroot", tf_sysroot]
     result = raw_exec(repository_ctx, [cc, "-E", "-x" + lang, "-", "-v"] +
                                       sysroot)
-    index1 = result.stderr.find(_INC_DIR_MARKER_BEGIN)
+    stderr = err_out(result)
+    index1 = stderr.find(_INC_DIR_MARKER_BEGIN)
     if index1 == -1:
         return []
-    index1 = result.stderr.find("\n", index1)
+    index1 = stderr.find("\n", index1)
     if index1 == -1:
         return []
-    index2 = result.stderr.rfind("\n ")
+    index2 = stderr.rfind("\n ")
     if index2 == -1 or index2 < index1:
         return []
-    index2 = result.stderr.find("\n", index2 + 1)
+    index2 = stderr.find("\n", index2 + 1)
     if index2 == -1:
-        inc_dirs = result.stderr[index1 + 1:]
+        inc_dirs = stderr[index1 + 1:]
     else:
-        inc_dirs = result.stderr[index1 + 1:index2].strip()
+        inc_dirs = stderr[index1 + 1:index2].strip()
 
     return [
         _normalize_include_path(repository_ctx, _cxx_inc_convert(p))
@@ -346,7 +348,7 @@ def _cuda_include_path(repository_ctx, cuda_config):
     cmd = "%s -v /dev/null -o /dev/null ; [ $? -eq 1 ]" % str(nvcc_path)
     result = raw_exec(repository_ctx, [get_bash_bin(repository_ctx), "-c", cmd])
     target_dir = ""
-    for one_line in result.stderr.splitlines():
+    for one_line in err_out(result).splitlines():
         if one_line.startswith("#$ _TARGET_DIR_="):
             target_dir = (
                 cuda_config.cuda_toolkit_path + "/" + one_line.replace(
@@ -600,7 +602,7 @@ def find_cuda_config(repository_ctx, script_path, cuda_libraries):
         script_path,
     ] + cuda_libraries)
     if exec_result.return_code:
-        auto_configure_fail("Failed to run find_cuda_config.py: %s" % exec_result.stderr)
+        auto_configure_fail("Failed to run find_cuda_config.py: %s" % err_out(exec_result))
 
     # Parse the dict from stdout.
     return dict([tuple(x.split(": ")) for x in exec_result.stdout.splitlines()])

third_party/gpus/rocm_configure.bzl

@@ -21,6 +21,7 @@ load(
 )
 load(
     "//third_party/remote_config:common.bzl",
+    "err_out",
     "execute",
     "files_exist",
     "get_bash_bin",
@@ -116,20 +117,21 @@ def _get_cxx_inc_directories_impl(repository_ctx, cc, lang_is_cpp):
         "-",
         "-v",
     ])
-    index1 = result.stderr.find(_INC_DIR_MARKER_BEGIN)
+    stderr = err_out(result)
+    index1 = stderr.find(_INC_DIR_MARKER_BEGIN)
     if index1 == -1:
         return []
-    index1 = result.stderr.find("\n", index1)
+    index1 = stderr.find("\n", index1)
     if index1 == -1:
         return []
-    index2 = result.stderr.rfind("\n ")
+    index2 = stderr.rfind("\n ")
     if index2 == -1 or index2 < index1:
         return []
-    index2 = result.stderr.find("\n", index2 + 1)
+    index2 = stderr.find("\n", index2 + 1)
     if index2 == -1:
-        inc_dirs = result.stderr[index1 + 1:]
+        inc_dirs = stderr[index1 + 1:]
     else:
-        inc_dirs = result.stderr[index1 + 1:index2].strip()
+        inc_dirs = stderr[index1 + 1:index2].strip()
 
     return [
         str(repository_ctx.path(_cxx_inc_convert(p)))

third_party/remote_config/common.bzl

@@ -260,3 +260,19 @@ def realpath(repository_ctx, path, bash_bin = None):
         bash_bin = get_bash_bin(repository_ctx)
 
     return execute(repository_ctx, [bash_bin, "-c", "realpath %s" % path]).stdout.strip()
+
+def err_out(result):
+    """Returns stderr if set, else stdout.
+
+    This function is a workaround for a bug in RBE where stderr is returned as stdout. Instead
+    of using result.stderr use err_out(result) instead.
+
+    Args:
+      result: the exec_result.
+
+    Returns:
+      The stderr if set, else stdout
+    """
+    if len(result.stderr) == 0:
+        return result.stdout
+    return result.stderr