Windows sccache errors on CI with socket error

[ehuss]

Recently there have been some errors on the Windows runners while building llvm with this error:

885/3793] Building CXX object lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/InstrProfiling.cpp.obj
FAILED: lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/InstrProfiling.cpp.obj 
sccache D:\a\rust\rust\mingw64\bin\g++.exe -DEXPERIMENTAL_KEY_INSTRUCTIONS -DGTEST_HAS_RTTI=0 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -ID:/a/rust/rust/build/x86_64-pc-windows-gnu/llvm/build/lib/Transforms/Instrumentation -ID:/a/rust/rust/src/llvm-project/llvm/lib/Transforms/Instrumentation -ID:/a/rust/rust/build/x86_64-pc-windows-gnu/llvm/build/include -ID:/a/rust/rust/src/llvm-project/llvm/include -ffunction-sections -fdata-sections -m64 -Wa,-mbig-obj -Werror=date-time -w -ffunction-sections -fdata-sections  -O2 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/InstrProfiling.cpp.obj -MF lib\Transforms\Instrumentation\CMakeFiles\LLVMInstrumentation.dir\InstrProfiling.cpp.obj.d -o lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/InstrProfiling.cpp.obj -c D:/a/rust/rust/src/llvm-project/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
sccache: error: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full. (os error 10055)
[886/3793] Building CXX object lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/MemProfUse.cpp.obj
[887/3793] Building CXX object lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/NumericalStabilitySanitizer.cpp.obj
[888/3793] Building CXX object lib/Transforms/Instrumentation/CMakeFiles/LLVMInstrumentation.dir/IndirectCallPromotion.cpp.obj
ninja: build stopped: subcommand failed.

thread 'main' (4120) panicked at C:\Users\runneradmin\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\cmake-0.1.54\src\lib.rs:1119:5:

command did not execute successfully, got: exit code: 1

Seen in:

• x86_64-mingw-1: Emit error when using path-segment keyword as cfg pred #146978 (comment)
• aarch64-msvc-2: Rollup of 8 pull requests #147440 (comment)
• dist-aarch64-msvc: Clippy subtree update #148340 (comment)

[ChrisDenton]

WSAENOBUFS usually indicates a leak somewhere (e.g. something somewhere is holding on to socket buffers). Can be a pain to diagnose though, especially if it only happens intermittently.