package build failing non-deterministically on Windows: race on dual dll copies?

Friday's package build failed: https://github.com/DynamoRIO/dynamorio/runs/1672245697

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[259/585] Linking C shared library lib64\release\dynamorio.dll
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   Creating library lib64\release\dynamorio.lib and object lib64\release\dynamorio.exp
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LINK : warning LNK4281: undesirable base address 0x71000000 for x64 image; set base address above 4GB for best ASLR optimization
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737
[493/585] Linking C executable clients\bin64\winsysnums.exe

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[531/585] Linking CXX executable clients\bin64\opcode_mix_launcher.exe

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[536/585] Linking CXX executable clients\bin64\drcov2lcov.exe
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   Creating library clients\lib64\release\drcov2lcov.lib and object clients\lib64\release\drcov2lcov.exp
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[537/585] Generating drcov.dox
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[538/585] Linking CXX executable clients\bin64\drcachesim.exe
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FAILED: clients/bin64/drcachesim.exe 
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cmd.exe /C "cd . && "C:\Program Files\CMake\bin\cmake.exe" -E vs_link_exe --intdir=clients\drcachesim\CMakeFiles\drcachesim.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100177~1.0\x86\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100177~1.0\x86\mt.exe --manifests  -- C:\PROGRA~2\MICROS~1\2017\ENTERP~1\VC\Tools\MSVC\1416~1.270\bin\Hostx64\x64\link.exe /nologo clients\drcachesim\CMakeFiles\drcachesim.dir\launcher.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\analyzer.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\analyzer_multi.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\common\named_pipe_win.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\common\options.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\common\trace_entry.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\reader\reader.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\reader\config_reader.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\reader\file_reader.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\reader\ipc_reader.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\simulator\analyzer_interface.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\tracer\instru.cpp.obj clients\drcachesim\CMakeFiles\drcachesim.dir\tracer\instru_online.cpp.obj  /out:clients\bin64\drcachesim.exe /implib:clients\lib64\release\drcachesim.lib /pdb:clients\bin64\drcachesim.pdb /version:0.0 /machine:x64 /subsystem:console,5.02 /opt:ref /opt:icf /pdbcompress /debug   /subsystem:console  /opt:ref /opt:icf /pdbcompress /nodefaultlib:libcmt  libcpmt.lib  libcmt.lib  libvcruntime.lib  libucrt.lib  clients\lib64\release\drmemtrace_simulator.lib  clients\lib64\release\drmemtrace_reuse_distance.lib  clients\lib64\release\drmemtrace_histogram.lib  clients\lib64\release\drmemtrace_reuse_time.lib  clients\lib64\release\drmemtrace_basic_counts.lib  clients\lib64\release\drmemtrace_opcode_mix.lib  clients\lib64\release\drmemtrace_view.lib  clients\lib64\release\drmemtrace_func_view.lib  clients\lib64\release\drmemtrace_raw2trace.lib  clients\lib64\release\directory_iterator.lib  lib64\drdecode.lib  lib64\drinjectlib.lib  lib64\drconfiglib.lib  lib64\drfrontendlib.lib  ext\lib64\release\drcovlib_static.lib  ext\lib64\release\drutil_static.lib  libcpmt.lib  libcmt.lib  libvcruntime.lib  libucrt.lib  lib64\drdecode.lib  kernel32.lib  advapi32.lib  imagehlp.lib  lib64\drlibc.lib  ext\lib64\release\drx_static.lib  lib64\ntdll_imports.lib  ext\lib64\release\drreg_static.lib  ext\lib64\release\drmgr_static.lib  ext\lib64\release\drcontainers.lib  lib64\release\dynamorio.lib  kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cmd.exe /C "cd /D D:\a\dynamorio\dynamorio\build_release-64\clients\drcachesim && "C:\Program Files\CMake\bin\cmake.exe" -E copy D:/a/dynamorio/dynamorio/build_release-64/lib64/drinjectlib.dll D:/a/dynamorio/dynamorio/build_release-64/clients/bin64/drinjectlib.dll && cd /D D:\a\dynamorio\dynamorio\build_release-64\clients\drcachesim && "C:\Program Files\CMake\bin\cmake.exe" -E copy D:/a/dynamorio/dynamorio/build_release-64/lib64/drconfiglib.dll D:/a/dynamorio/dynamorio/build_release-64/clients/bin64/drconfiglib.dll && cd /D D:\a\dynamorio\dynamorio\build_release-64\clients\drcachesim && "C:\Program Files\CMake\bin\cmake.exe" -E copy D:/a/dynamorio/dynamorio/build_release-64/lib64/release/dynamorio.dll D:/a/dynamorio/dynamorio/build_release-64/clients/bin64/dynamorio.dll""
888
   Creating library clients\lib64\release\drcachesim.lib and object clients\lib64\release\drcachesim.exp
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Error copying file "D:/a/dynamorio/dynamorio/build_release-64/lib64/release/dynamorio.dll" to "D:/a/dynamorio/dynamorio/build_release-64/clients/bin64/dynamorio.dll".

So clearly dynamorio.dll has been created, and the clients/bin64 directory exists.

A race between drcov2lcov and drcachesim both copying dynamorio.dll into clients/bin64? Maybe "CMake -E copy" checks for existence and has no error if there's a clear ordering and one copy finishes first, but here drcov2lcov and drcachesim are both doing the copy at the same time and the 2nd one's existence check says nothing is there but then the copy fails because the first is currently writing to it with a file lock?