SIGSEGV in LinearScan::RegisterSelection::try_SPILL_COST in VMR build of .NET 10 Preview 7

[omajid]

Description

I built .NET 10 Preview 7 on CentOS Stream 10 using the VMR ("bootstrap build"). When I use that just-built SDK (the "bootstrap build") to build the VMR again, the SDK crashes.

Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007f5b01a01868 in LinearScan::RegisterSelection::try_SPILL_COST (this=0x7f5afc13f628) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/lsra.cpp:13078
13078               if ((linearScan->getNextIntervalRef(spillCandidateRegNum, regType) == thisLocation) &&
[Current thread is 1 (Thread 0x7f5b02bff6c0 (LWP 1399195))]
Missing rpms, try: dnf --enablerepo='*debug*' install glibc-debuginfo-2.39-54.el10.x86_64
(gdb) bt
#0  0x00007f5b01a01868 in LinearScan::RegisterSelection::try_SPILL_COST (this=0x7f5afc13f628) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/lsra.cpp:13078
#1  0x00007f5b01a013ed in LinearScan::RegisterSelection::select<false> (this=0x7f5afc13f628, currentInterval=0x7f5afc13fc00, refPosition=0x7f5afc13fc60) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/lsra_score.h:41
#2  0x00007f5b019fa7c7 in LinearScan::allocateReg<false> (this=0x7f5afc13d920, currentInterval=0xc, refPosition=0xe38) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/lsra.cpp:2945
#3  0x00007f5b019f3243 in LinearScan::allocateRegisters (this=0x7f5afc13d920) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/lsra.cpp:6583
#4  0x00007f5b019f0a99 in LinearScan::doLinearScan (this=0x7f5afc13d920) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/lsra.cpp:1350
#5  0x00007f5b018e5208 in Compiler::compCompile(void**, unsigned int*, JitFlags*)::$_5::operator()() const (this=<optimized out>) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:5001
#6  ActionPhase<Compiler::compCompile(void**, unsigned int*, JitFlags*)::$_5>::DoPhase (this=<optimized out>) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/phase.h:69
#7  0x00007f5b01a451dc in Phase::Run (this=0x7f5b02bfdce0) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/phase.cpp:61
#8  0x00007f5b018e0e44 in DoPhase<Compiler::compCompile(void**, unsigned int*, JitFlags*)::$_5>(Compiler*, Phases, Compiler::compCompile(void**, unsigned int*, JitFlags*)::$_5) (_compiler=0x7f5afc135028, _phase=PHASE_LINEAR_SCAN, _action=...)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/phase.h:83
#9  Compiler::compCompile (this=0x7f5afc135028, methodCodePtr=0x7f5b02bfe388, methodCodeSize=0x7f5b02bfe47c, compileFlags=<optimized out>) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:5003
#10 0x00007f5b018e3457 in Compiler::compCompileHelper (this=0x7f5afc135028, classPtr=0x7fb976e54000, compHnd=<optimized out>, methodInfo=0x7f5b02bfe558, methodCodePtr=0x7f5b02bfe388, methodCodeSize=0x7f5b02bfe47c, compileFlags=0x7f5b02bfe3b0)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:7086
#11 0x00007f5b018e22e1 in Compiler::compCompile(CORINFO_MODULE_STRUCT_*, void**, unsigned int*, JitFlags*)::$_0::operator()(Compiler::compCompile(CORINFO_MODULE_STRUCT_*, void**, unsigned int*, JitFlags*)::__JITParam*) const (this=<optimized out>, __JITpParam=<optimized out>)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:6274
#12 Compiler::compCompile (this=0x7f5afc135028, classPtr=0x7fb976e54000, methodCodePtr=0x7f5b02bfe388, methodCodeSize=0x7f5b02bfe47c, compileFlags=0x7f5b02bfe3b0)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:6293
#13 0x00007f5b018e3e77 in jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::$_0::operator()(jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::__JITParam*) const::{lambda(jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::$_0::operator()(jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::__JITParam*) const::__JITParam*)#1}::operator()(jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::$_0::operator()(jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::__JITParam*) const::__JITParam*) const (this=<optimized out>, __JITpParam=<optimized out>)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:7732
#14 jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::$_0::operator()(jitNativeCode(CORINFO_METHOD_STRUCT_*, CORINFO_MODULE_STRUCT_*, ICorJitInfo*, CORINFO_METHOD_INFO*, void**, unsigned int*, JitFlags*, void*)::__JITParam*) const (this=<optimized out>, __JITpParam=<optimized out>) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:7756
#15 jitNativeCode (methodHnd=0x7fb978920450, classPtr=0x7fb976e54000, compHnd=0x7f5b02bfe4d0, methodInfo=0x7f5b02bfe558, methodCodePtr=0x7f5b02bfe388, methodCodeSize=0x7f5b02bfe47c, compileFlags=0x7f5b02bfe3b0, inlineInfoPtr=0x0)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/compiler.cpp:7758
#16 0x00007f5b018e82cc in CILJit::compileMethod (this=<optimized out>, compHnd=0x7f5b02bfe4d0, methodInfo=0x7f5b02bfe558, flags=<optimized out>, entryAddress=0x7f5b02bfe480, nativeSizeOfCode=0x7f5b02bfe47c)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/jit/ee_il_dll.cpp:302
#17 0x00007fb9f61b7e7a in invokeCompileMethod (jitMgr=0x555d73561910, comp=0x7f5b02bfe4d0, nativeEntry=0x7f5b02bfe480, nativeSizeOfCode=0x7f5b02bfe47c, nativeCodeVersion=...)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/jitinterface.cpp:12833
#18 UnsafeJitFunctionWorker (pJitMgr=0x555d73561910, pJitInfo=0x7f5b02bfe4d0, nativeCodeVersion=..., pSizeOfCode=0x7f5b02bfe8cc) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/jitinterface.cpp:13056
#19 UnsafeJitFunction (config=0x7f5b02bfeab8, ILHeader=0x7f5b02bfe890, isTier0=0x7f5b02bfe797, isInterpreterCode=0x7f5b02bfe88f, pSizeOfCode=0x7f5b02bfe8cc) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/jitinterface.cpp:13384
#20 0x00007fb9f61f45fa in MethodDesc::JitCompileCodeLocked (this=0x7fb978920450, pConfig=0x7f5b02bfeab8, pilHeader=0x7f5b02bfe890, pEntry=0x7f5afc1bd070, pSizeOfCode=0x7f5b02bfe8cc, pIsInterpreterCode=0x7f5b02bfe88f)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/prestub.cpp:916
#21 0x00007fb9f61f3edf in MethodDesc::JitCompileCodeLockedEventWrapper (this=0x7fb978920450, pConfig=0x7f5b02bfeab8, pEntry=0x7f5afc1bd070) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/prestub.cpp:814
#22 0x00007fb9f61f35fe in MethodDesc::JitCompileCode (this=0x7fb978920450, pConfig=0x7f5b02bfeab8) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/prestub.cpp:694
#23 0x00007fb9f61f30a6 in MethodDesc::PrepareILBasedCode (this=0x7fb978920450, pConfig=0x7f5b02bfeab8) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/prestub.cpp:424
#24 0x00007fb9f6224d18 in TieredCompilationManager::CompileCodeVersion (this=<optimized out>, nativeCodeVersion=...) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/tieredcompilation.cpp:956
#25 0x00007fb9f62240a0 in TieredCompilationManager::OptimizeMethod (this=0x555d735141f0, nativeCodeVersion=...) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/tieredcompilation.cpp:933
#26 TieredCompilationManager::DoBackgroundWork (this=0x555d735141f0, workDurationTicksRef=0x7f5b02bfec68, minWorkDurationTicks=50000000, maxWorkDurationTicks=50000000)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/tieredcompilation.cpp:819
#27 0x00007fb9f62236a5 in TieredCompilationManager::BackgroundWorkerStart (this=0x555d735141f0) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/tieredcompilation.cpp:533
#28 0x00007fb9f622351c in TieredCompilationManager::BackgroundWorkerBootstrapper1 () at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/tieredcompilation.cpp:483
#29 0x00007fb9f621fb7d in ManagedThreadBase_DispatchInner (pCallState=<optimized out>) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/threads.cpp:6832
#30 ManagedThreadBase_DispatchMiddle (pCallState=0xfe) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/threads.cpp:6876
#31 ManagedThreadBase_DispatchOuter(ManagedThreadCallState*)::$_0::operator()(ManagedThreadBase_DispatchOuter(ManagedThreadCallState*)::TryArgs*) const::{lambda(Param*)#1}::operator()(Param*) const (this=<optimized out>, pParam=<optimized out>)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/threads.cpp:7034
#32 ManagedThreadBase_DispatchOuter(ManagedThreadCallState*)::$_0::operator()(ManagedThreadBase_DispatchOuter(ManagedThreadCallState*)::TryArgs*) const (this=<optimized out>, pArgs=<optimized out>)
    at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/threads.cpp:7036
#33 ManagedThreadBase_DispatchOuter (pCallState=0x7f5b02bfecf8) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/threads.cpp:7060
#34 ManagedThreadBase::KickOff (pTarget=<optimized out>, args=<optimized out>) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/threads.cpp:7074
#35 0x00007fb9f6223444 in TieredCompilationManager::BackgroundWorkerBootstrapper0 (args=0x555d735367c0) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/vm/tieredcompilation.cpp:464
#36 0x00007fb9f645efd2 in CorUnix::CPalThread::ThreadEntry (pvParam=0x555d73557cc0) at /usr/src/debug/dotnet10.0-10.0.100~preview.7.25380.108-0.7.el10.x86_64/src/runtime/src/coreclr/pal/src/thread/thread.cpp:1618
#37 0x00007fb9f680e128 in start_thread () from /lib64/libc.so.6
#38 0x00007fb9f687eafc in clone3 () from /lib64/libc.so.6

I see the same behaviour on both Preview 6 and Preview 7 releases.

Reproduction Steps

The first SDK was compiled with:

$ export CFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS --config=/usr/lib/rpm/redhat/redhat-hardened-clang.cfg -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
$ export CXXFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS --config=/usr/lib/rpm/redhat/redhat-hardened-clang.cfg -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
$ export LDFLAGS='-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now --config=/usr/lib/rpm/redhat/redhat-hardened-clang-ld.cfg   -Wl,--build-id=sha1  '
$ export 'EXTRA_CFLAGS=-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS --config=/usr/lib/rpm/redhat/redhat-hardened-clang.cfg -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
$ export 'EXTRA_CXXFLAGS=-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS --config=/usr/lib/rpm/redhat/redhat-hardened-clang.cfg -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
$ export 'EXTRA_LDFLAGS=-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now --config=/usr/lib/rpm/redhat/redhat-hardened-clang-ld.cfg   -Wl,--build-id=sha1  '
$ EXTRA_LDFLAGS='-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now --config=/usr/lib/rpm/redhat/redhat-hardened-clang-ld.cfg   -Wl,--build-id=sha1  '
$ ./build.sh --source-only --release-manifest /home/omajid/dotnet10.0/release.json -- /p:UseSystemLibs=+brotli++zlib+-lttng- /p:TargetRid=centos.10-x64 /p:OfficialBuilder=CentOS /p:MinimalConsoleLogOutput=false /p:ContinueOnPrebuiltBaselineError=true /v:n /p:LogVerbosity=n

Expected behavior

No crash

Actual behavior

crash

Regression?

Yes. I don't see any such crashes on .NET 9.

I tried testing with older .NET 10 preview releases, but Preview 5 doesn't even build anymore.

Known Workarounds

No response

Configuration

No response

Other information

No response

[AndyAyersMS]

fyi @dotnet/jit-contrib

@omajid you don't happen to have a crash dump handy...? If not, can you add some more detailed repro instructions. In particular: how do you do the second build, and is there a docker image I can use?

Edit: found some info in the dotnet/dotnet readme which I am following for now, as well as the bootstrapping guidelines.

[dotnet-policy-service]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.

[AndyAyersMS]

The second build in the bootstrapping doesn't seem to do much of anything, so perhaps the instructions are missing a step (eg cleaning the vmr repo...?)

[omajid]

Yes, I need to find/test better steps to reproduce in isolation. I have a complex environment where this reproduces consistently, but it doesn't reproduce in other environments where I can run things one by one manually.

With some quick testing, building with -march=x86-64-v3 seems to be the root cause of breaking the jit.

[AndyAyersMS]

I haven't had any luck reproing yet...

Now following these instructions for the bootstrap.

Which clang version are you using? Which build fails? What kind of machine are you building on?

[tmds]

@AndyAyersMS probably this is going to need a specific environment to reproduce. If I understood @omajid correctly, this issue happened on CentOS Stream 10, but not on RHEL 10, even though both should be very similar (like including -march=x86-64-v3).

[omajid]

Here are my steps to reproduce on CentOS Stream 10:

#!/bin/bash

set -euo pipefail          
set -x                                                                                    
                                                                                          
uname -m
cat /etc/os-release
rpm -q clang gcc lld llvm 
                                             
rm -rf self-built         
mkdir -p self-built

pushd dotnet
git clean -xdf
git checkout -- .
git checkout release/10.0.1xx

patch -p1 <<EOF
diff --git dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt
index cca2c6da185..d31e6cb2070 100644
--- dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt
+++ dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt
@@ -52,6 +52,7 @@ if(CLR_CMAKE_HOST_UNIX)
   add_compile_options(-Wno-array-bounds)
   add_compile_options(-Wno-unused-label)
   set_source_files_properties( prebuilt/asmparse.cpp PROPERTIES COMPILE_FLAGS "-O0" )
+  set_source_files_properties( prebuilt/asmparse.cpp PROPERTIES COMPILE_FLAGS "-Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=0" )
 endif(CLR_CMAKE_HOST_UNIX)

 if(CLR_CMAKE_HOST_LINUX OR CLR_CMAKE_HOST_FREEBSD OR CLR_CMAKE_HOST_NETBSD OR CLR_CMAKE_HOST_SUNOS OR CLR_CMAKE_HOST_HAIKU)
EOF

export CFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-s
trong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
export CXXFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector
-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
export LDFLAGS='-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now  -Wl,--build-id=sha1  '
export EXTRA_CFLAGS=$CFLAGS
export EXTRA_CXXFLAGS=$CXXFLAGS
export EXTRA_LDFLAGS=$LDFLAGS


./build.sh --prep --source-only

cp -a ./artifacts/assets/Release/Sdk/10.0*/dotnet-sdk-10.*-x64.tar.gz ../self-built/
cp -a ./artifacts/assets/Release/Private.SourceBuilt.Artifacts.*-x64.tar.gz ../self-built/ 

popd

pushd self-built

mkdir -p sdk
pushd sdk
tar xf ../dotnet-sdk-*tar.gz
popd

mkdir -p packages
pushd packages
tar xf ../Private.SourceBuilt.Artifacts*.tar.gz
popd

popd

cd dotnet
git clean -xdf
git checkout -- .

patch -p1 <<EOF
diff --git dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt
index cca2c6da185..d31e6cb2070 100644
--- dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt
+++ dotnet/src/runtime/src/coreclr/ilasm/CMakeLists.txt
@@ -52,6 +52,7 @@ if(CLR_CMAKE_HOST_UNIX)
   add_compile_options(-Wno-array-bounds)
   add_compile_options(-Wno-unused-label)
   set_source_files_properties( prebuilt/asmparse.cpp PROPERTIES COMPILE_FLAGS "-O0" )
+  set_source_files_properties( prebuilt/asmparse.cpp PROPERTIES COMPILE_FLAGS "-Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=0" )
 endif(CLR_CMAKE_HOST_UNIX)

 if(CLR_CMAKE_HOST_LINUX OR CLR_CMAKE_HOST_FREEBSD OR CLR_CMAKE_HOST_NETBSD OR CLR_CMAKE_HOST_SUNOS OR CLR_CMAKE_HOST_HAIKU)
EOF

./build.sh  --source-only \
        --with-sdk "$(readlink -f ../self-built/sdk/)" \
        --with-packages "$(readlink -f ../self-built/packages)" \



echo done

Top of the output showing my environment:

+ uname -m
x86_64
+ cat /etc/os-release
NAME="CentOS Stream"
VERSION="10 (Coughlan)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="10"
PLATFORM_ID="platform:el10"
PRETTY_NAME="CentOS Stream 10 (Coughlan)"
ANSI_COLOR="0;31"
LOGO="fedora-logo-icon"
CPE_NAME="cpe:/o:centos:centos:10"
HOME_URL="https://centos.org/"
VENDOR_NAME="CentOS"
VENDOR_URL="https://centos.org/"
BUG_REPORT_URL="https://issues.redhat.com/"
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux 10"
REDHAT_SUPPORT_PRODUCT_VERSION="CentOS Stream"
+ rpm -q clang gcc lld llvm
clang-20.1.8-1.el10.x86_64
gcc-14.3.1-2.1.el10.x86_64
lld-20.1.8-1.el10.x86_64
llvm-20.1.8-1.el10.x86_64
+ rm -rf self-built
+ mkdir -p self-built
+ pushd dotnet
~/dotnet ~
+ git clean -xdf
Removing src/runtime/src/coreclr/ilasm/CMakeLists.txt.orig
+ git checkout -- .
+ git checkout release/10.0.1xx
Already on 'release/10.0.1xx'
Your branch is up to date with 'origin/release/10.0.1xx'.
+ patch -p1
patching file src/runtime/src/coreclr/ilasm/CMakeLists.txt
Hunk #1 succeeded at 62 (offset 10 lines).
+ export 'CFLAGS=-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ CFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ export 'CXXFLAGS=-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ CXXFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ export 'LDFLAGS=-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now  -Wl,--build-id=sha1  '
+ LDFLAGS='-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now  -Wl,--build-id=sha1  '
+ export 'EXTRA_CFLAGS=-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ EXTRA_CFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ export 'EXTRA_CXXFLAGS=-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ EXTRA_CXXFLAGS='-O2 -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -fstack-protector-strong -m64 -march=x86-64-v3 -mtune=generic -fasynchronous-unwind-tables  -fcf-protection -Wno-used-but-marked-unused'
+ export 'EXTRA_LDFLAGS=-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now  -Wl,--build-id=sha1  '
+ EXTRA_LDFLAGS='-Wl,-z,relro -Wl,--as-needed  -Wl,-z,pack-relative-relocs -Wl,-z,now  -Wl,--build-id=sha1  '
+ ./build.sh --prep --source-only
  Installing dotnet...
...

The second invocation of build.sh fails really fast with the segfault:

+ ./build.sh --source-only --with-sdk /home/omajid/self-built/sdk --with-packages /home/omajid/self-built/packages
NuGet packages cache: '/home/omajid/dotnet/.packages/'
Using custom bootstrap SDK from '/home/omajid/self-built/sdk', version '10.0.100-dev'
Found bootstrap versions: SDK 10.0.100-dev, Arcade 10.0.0-dev, NoTargets 3.7.0 and Traversal 3.4.0

Welcome to .NET 10.0!
---------------------
SDK Version: 10.0.100-dev

----------------
Installed an ASP.NET Core HTTPS development certificate.
To trust the certificate, run 'dotnet dev-certs https --trust'
Learn about HTTPS: https://aka.ms/dotnet-https

----------------
Write your first app: https://aka.ms/dotnet-hello-world
Find out what's new: https://aka.ms/dotnet-whats-new
Explore documentation: https://aka.ms/dotnet-docs
Report issues and find source on GitHub: https://github.com/dotnet/core
Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli
--------------------------------------------------------------------------------------
Shutting down MSBuild server...
MSBuild server shut down successfully.

  Determining projects to restore...
  Restored /home/omajid/dotnet/eng/tools/tasks/Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver/Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver.csproj (in 342 ms).
  Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver -> /home/omajid/dotnet/artifacts/bin/Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver/Release/Microsoft.DotNet.UnifiedBuild.MSBuildSdkResolver.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:04.00
Shutting down MSBuild server...
MSBuild server shut down successfully.
  
  Determining projects to restore...
  Restored /home/omajid/dotnet/.packages/BootstrapPackages/microsoft.dotnet.arcade.sdk/10.0.0-dev/tools/Tools.proj (in 283 ms).  
  Determining projects to restore...  
/home/omajid/dotnet/eng/common/tools.sh: line 507: 3972224 Segmentation fault      (core dumped) "$_InitializeBuildTool" "$@" 
Build failed with exit code 139. Check errors above.