I have a CL which doesn't seem to do anything out of the ordinary, yet it consistently hits an assert on Windows clang. The CL is https://chromium-review.googlesource.com/c/611102.

Example failure is https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Ftryserver.chromium.win%2Fwin_chromium_rel_ng%2F515514%2F%2B%2Frecipes%2Fsteps%2Fcompile__with_patch_%2F0%2Fstdout


FAILED: obj/content/test/content_browsertests/isolated_origin_browsertest.obj 
E:\b\c\goma_client/gomacc.exe ../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes  @obj/content/test/content_browsertests/isolated_origin_browsertest.obj.rsp /c ../../content/browser/isolated_origin_browsertest.cc /Foobj/content/test/content_browsertests/isolated_origin_browsertest.obj /Fd"obj/content/test/content_browsertests_cc.pdb"
Assertion failed: !isInAllocaArgument(CGM.getCXXABI(), type) && "cannot emit delegate call arguments for inalloca arguments!", file E:\b\build\slave\win_upload_clang\build\src\third_party\llvm\tools\clang\lib\CodeGen\CGCall.cpp, line 3014
Wrote crash dump file "C:\Users\CHROME~2\AppData\Local\Temp\goma\goma_temp.636\clang-cl.exe-0cff90.dmp"
#0 0x0000000141453fc6 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x17a3fc6)
#1 0x00000001432177d5 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x35677d5)
#2 0x000000014320f218 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x355f218)
#3 0x000000014320797a (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x355797a)
#4 0x0000000143207a16 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x3557a16)
#5 0x0000000141823714 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1b73714)
#6 0x0000000141862472 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1bb2472)
#7 0x00000001417b62df (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1b062df)
#8 0x0000000141653d70 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x19a3d70)
#9 0x000000014164ec86 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x199ec86)
#10 0x0000000141648d5a (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1998d5a)
#11 0x0000000141648d82 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1998d82)
#12 0x000000014164805e (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x199805e)
#13 0x00000001431d83e5 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x35283e5)
#14 0x00000001431d6538 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x3526538)
#15 0x0000000141ad4e0c (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1e24e0c)
#16 0x00000001421da0a2 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x252a0a2)
#17 0x0000000141a9048c (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1de048c)
#18 0x0000000141a7dfb1 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1dcdfb1)
#19 0x0000000141b066da (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x1e566da)
#20 0x000000013fcb655d (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x655d)
#21 0x000000013fcb2113 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x2113)
#22 0x00000001431ff141 (E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe+0x354f141)
#23 0x00000000778f59bd (C:\Windows\system32\kernel32.dll+0x159bd)
#24 0x0000000077a2a2e1 (C:\Windows\SYSTEM32\ntdll.dll+0x2a2e1)
clang-cl.exe: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 6.0.0 (trunk 310694)
Target: i386-pc-windows-msvc
Thread model: posix
InstalledDir: E:\b\c\b\win\src\third_party\llvm-build\Release+Asserts\bin
clang-cl.exe: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ and include the crash backtrace, preprocessed source, and associated run script.
clang-cl.exe: note: diagnostic msg: 
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-cl.exe: note: diagnostic msg: C:\Users\CHROME~2\AppData\Local\Temp\goma\goma_temp.636\isolated_origin_browsertest-c835d9.sh
clang-cl.exe: note: diagnostic msg: 
********************