Assertion `CapturedVar->isInitCapture()' failed

[dcb314]

Recent clang says:

clang++: /home/dcb40b/llvm/trunk/clang/lib/Sema/SemaConcept.cpp:719: clang::Sema::addInstantiatedCapturesToScope(clang::FunctionDecl*, const clang::FunctionDecl*, clang::LocalInstantiationScope&, const clang::MultiLevelTemplateArgumentList&)::<lambda(const clang::ValueDecl*, unsigned int)>: Assertion `CapturedVar->isInitCapture()' failed.

connectionencryptiondata_p-e2be0f.sh.gz
connectionencryptiondata_p-e2be0f.cpp.gz

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: None (dcb314)

Recent clang says:

clang++: /home/dcb40b/llvm/trunk/clang/lib/Sema/SemaConcept.cpp:719: clang::Sema::addInstantiatedCapturesToScope(clang::FunctionDecl*, const clang::FunctionDecl*, clang::LocalInstantiationScope&, const clang::MultiLevelTemplateArgumentList&)::<lambda(const clang::ValueDecl*, unsigned int)>: Assertion `CapturedVar->isInitCapture()' failed.

connectionencryptiondata_p-e2be0f.sh.gz
connectionencryptiondata_p-e2be0f.cpp.gz

[zyn0217]

Reduced by me and CReduce:

(The crash only triggers w/ assertion build)

template <int N> void connect() {
  int x = N, y = N;
  [x, y = y]()
    requires requires { x; }
  {}();
}

void foo() {
  connect<42>();
}

https://godbolt.org/z/nqs6x31Gx

[shafik]

Looks like a regression on trunk: https://godbolt.org/z/h9frKK74Y

CC @cor3ntin

[dcb314]

Seems to go wrong sometime before or on date 2024-09-03.
Git hash 4d8903b.