Error from gclient sync when checking out Chromium 69.0.3497.100 on macOS

[mic...@micbel.com]

I'm having trouble trying to build Chromium 69.0.3497.100 from source on macOS, and I'm having trouble checking everything out.

First, in /<my-local-path>/chromium:

gclient sync --nohooks --with_branch_heads --disable-syntax-validation --jobs 16

This succeeds.  Then, in /<my-local-path>/chromium/src:

git config --get remote.origin.url
git fetch
git fetch --tags
git rev-parse HEAD
git rev-parse refs/tags/69.0.3497.100
git checkout refs/tags/69.0.3497.100

All of this succeeds.  Then, in /<my-local-path>/chromium:

gclient sync --with_branch_heads --disable-syntax-validation --jobs 16

This last command fails with a non-zero exit status 1 and the following additional information:

Error: Command 'git checkout --quiet 9f9f41bdd831c0bd84eea252634ee52f769e9977' returned non-zero exit status 128 in /<my-local-path>/chromium/src/chrome/browser/resources/media_router/extension/src
fatal: reference is not a tree: 9f9f41bdd831c0bd84eea252634ee52f769e9977

Here is an excerpt from the Chromium DEPS file in /<my-local-path>/chromium/src/DEPS:

...
deps = {
  'src/chrome/browser/resources/media_router/extension/src':
    Var('chromium_git') + '/media_router.git' + '@' + '9f9f41bdd831c0bd84eea252634ee52f769e9977',
...

You will note that this is the exact directory and hex value that gclient is rejecting, as seen in the gclient sync error information provided above.

Any ideas on why this would occur or how to fix it?  Is something missing from the repository?

This is a roadblock issue for me.  Thanks in advance for any help you can provide.

[mic...@micbel.com]

I tried deleting the problematic directory (chromium/src/chrome/browser/resources/media_router/extension/src) and running the following again:

git checkout refs/tags/69.0.3497.100
gclient sync --no-history --with_branch_heads --disable-syntax-validation --jobs 16

The folder and its contents were restored, and the process was able to continue.  Then another similar failure occurred, exactly the same problem but with a different folder.  I deleted that folder and ran the commands above again, with the same result.  Ultimately, I had to repeat this procedure for all of the following 18 folders:

chromium/src/chrome/browser/resources/media_router/extension/src
chromium/src/native_client
chromium/src/media/cdm/api
chromium/src/third_party/breakpad/breakpad
chromium/src/third_party/dom_distiller_js/dist
chromium/src/third_party/icu
chromium/src/third_party/libFuzzer/src
chromium/src/third_party/libjpeg_turbo
chromium/src/third_party/googletest/src
chromium/src/third_party/depot_tools
chromium/src/third_party/leveldatabase/src
chromium/src/third_party/libprotobuf-mutator/src
chromium/src/third_party/libsrt
chromium/src/third_party/libyuv
chromium/src/third_party/catapult
chromium/src/third_party/quic_trace/src
chromium/src/tools/swarming_client
chromium/src/third_party/webgl/src

After that, the sync continued and eventually appeared to complete successfully.  Why was this process necessary?

Anyway, hopefully now the build will actually work.