https://build.chromium.org/p/chromium/builders/Win%20x64/builds/11755
https://build.chromium.org/p/chromium/builders/Win%20x64/builds/11756

The first build had a compile close to 2h, so I thought maybe it's just a timeout. The second build hit this after 1h.

(Also, postprocess_for_goma.upload_log takes 14min to run when goma errors occur, this might be a problem too.)

[48817/51111] CXX obj/chrome/test/unit_tests/security_state_tab_helper_unittest.obj
FAILED: obj/chrome/test/unit_tests/security_state_tab_helper_unittest.obj 
C:\b\c\goma_client/gomacc.exe ../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes /FC @obj/chrome/test/unit_tests/security_state_tab_helper_unittest.obj.rsp /c ../../chrome/browser/ssl/security_state_tab_helper_unittest.cc /Foobj/chrome/test/unit_tests/security_state_tab_helper_unittest.obj /Fd"obj/chrome/test/unit_tests_cc.pdb"
E0529 21:47:37.506515  3416 named_pipe_client_win.cc:42] Timed-out to create new pipe:\\.\pipe\goma.ipc
compiler proxy isn't running. Exiting.
[48818/51111] CXX obj/chrome/test/unit_tests/resource_prefetch_predictor_unittest.obj
FAILED: obj/chrome/test/unit_tests/resource_prefetch_predictor_unittest.obj 
C:\b\c\goma_client/gomacc.exe ../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes /FC @obj/chrome/test/unit_tests/resource_prefetch_predictor_unittest.obj.rsp /c ../../chrome/browser/predictors/resource_prefetch_predictor_unittest.cc /Foobj/chrome/test/unit_tests/resource_prefetch_predictor_unittest.obj /Fd"obj/chrome/test/unit_tests_cc.pdb"
E0529 21:47:37.504515  6684 named_pipe_client_win.cc:42] Timed-out to create new pipe:\\.\pipe\goma.ipc
compiler proxy isn't running. Exiting.
[48819/51111] CXX obj/chrome/test/unit_tests/chrome_signin_client_unittest.obj
FAILED: obj/chrome/test/unit_tests/chrome_signin_client_unittest.obj 
C:\b\c\goma_client/gomacc.exe ../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes /FC @obj/chrome/test/unit_tests/chrome_signin_client_unittest.obj.rsp /c ../../chrome/browser/signin/chrome_signin_client_unittest.cc /Foobj/chrome/test/unit_tests/chrome_signin_client_unittest.obj /Fd"obj/chrome/test/unit_tests_cc.pdb"
E0529 21:47:37.505515  6872 named_pipe_client_win.cc:42] Timed-out to create new pipe:\\.\pipe\goma.ipc
compiler proxy isn't running. Exiting.
[48820/51111] CXX obj/chrome/test/unit_tests/account_reconcilor_unittest.obj
FAILED: obj/chrome/test/unit_tests/account_reconcilor_unittest.obj 
C:\b\c\goma_client/gomacc.exe ../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes /FC @obj/chrome/test/unit_tests/account_reconcilor_unittest.obj.rsp /c ../../chrome/browser/signin/account_reconcilor_unittest.cc /Foobj/chrome/test/unit_tests/account_reconcilor_unittest.obj /Fd"obj/chrome/test/unit_tests_cc.pdb"
E0529 21:47:37.504515   992 named_pipe_client_win.cc:42] Timed-out to create new pipe:\\.\pipe\goma.ipc
compiler proxy isn't running. Exiting.
[48821/51111] CXX obj/chrome/test/unit_tests/download_status_updater_unittest.obj
FAILED: obj/chrome/test/unit_tests/download_status_updater_unittest.obj 
C:\b\c\goma_client/gomacc.exe ../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes /FC @obj/chrome/test/unit_tests/download_status_updater_unittest.obj.rsp /c ../../chrome/browser/download/download_status_updater_unittest.cc /Foobj/chrome/test/unit_tests/download_status_updater_unittest.obj /Fd"obj/chrome/test/unit_tests_cc.pdb"
E0529 21:47:37.504515  6636 named_pipe_client_win.cc:42] Timed-out to create new pipe:\\.\pipe\goma.ipc
compiler proxy isn't running. Exiting.


I will revert the clang switch soon, so this isn't urgent, but we need to fix it before we switch again.