It seems like on mac_chromium_rel_ng some try jobs are failing today in the analyze step unrelated to the try job patches. Doesn't seem to be happening on the continuous builders.

Recent builds:
https://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_ng

Example failure:
https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Ftryserver.chromium.mac%2Fmac_chromium_rel_ng%2F423266%2F%2B%2Frecipes%2Fsteps%2Fanalyze%2F0%2Fstdout

Log excerpt:
/b/c/b/mac/src/buildtools/mac/gn gen //out/Release --check
  -> returned 1
ERROR at //build/config/mac/mac_sdk.gni:61:5: Script returned non-zero exit code.
    exec_script("//build/mac/find_sdk.py", find_sdk_args, "list lines")
    ^----------
Current dir: /b/c/b/mac/src/out/Release/
Command: python -- /b/c/b/mac/src/build/mac/find_sdk.py --print_sdk_path 10.10
Returned 1.
stderr:

Traceback (most recent call last):
  File "/b/c/b/mac/src/build/mac/find_sdk.py", line 89, in <module>
    print main()
  File "/b/c/b/mac/src/build/mac/find_sdk.py", line 57, in main
    sdks = [re.findall('^MacOSX(10\.\d+)\.sdk$', s) for s in os.listdir(sdk_dir)]
OSError: [Errno 2] No such file or directory: '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs'

See //net/BUILD.gn:27:3: whence it was imported.
  import("//build/config/mac/mac_sdk.gni")
  ^--------------------------------------
See //BUILD.gn:81:5: which caused the file to be included.
    "//net:net_unittests",
    ^--------------------
GN gen failed: 1


Not quite sure who best to contact about this, or who would know what the root cause might be -- CCd some people who might know who else to CC :-)