<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/102745>102745</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang -std=c++23 -fmodules -stdlib=libc++  test.cpp failed
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          zyp2005
      </td>
    </tr>
</table>

<pre>
    ```
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      /usr/bin/../include/c++/v1/__system_error/error_condition.h:28:1: current parser token 'template'
1.      /usr/bin/../include/c++/v1/__system_error/error_condition.h:26:1 <Spelling=/usr/bin/../include/c++/v1/__config:884:39>: parsing namespace 'std'
 #0 0x00007c79adfc4d90 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/lib/libLLVM.so.18.1+0x7c4d90)
 #1 0x00007c79adfc1d4d (/usr/lib/libLLVM.so.18.1+0x7c1d4d)
 #2 0x00007c79ad24c1d0 (/usr/lib/libc.so.6+0x3d1d0)
 #3 0x00007c79b7886ed8 llvm::SmallVectorBase<unsigned int>::size() const /usr/include/llvm/ADT/SmallVector.h:91:32
 #4 0x00007c79b7886ed8 llvm::SmallVectorTemplateCommon<std::pair<clang::Decl*, clang::FunctionDecl*>, void>::end() /usr/include/llvm/ADT/SmallVector.h:282:41
 #5 0x00007c79b7886ed8 llvm::SmallVectorTemplateBase<std::pair<clang::Decl*, clang::FunctionDecl*>, true>::push_back(std::pair<clang::Decl*, clang::FunctionDecl*>) /usr/include/llvm/ADT/SmallVector.h:576:46
 #6 0x00007c79b7886ed8 std::pair<clang::Decl*, clang::FunctionDecl*>& llvm::SmallVectorTemplateBase<std::pair<clang::Decl*, clang::FunctionDecl*>, true>::growAndEmplaceBack<std::piecewise_construct_t const&, std::tuple<clang::Decl*&&>, std::tuple<clang::FunctionDecl*&&>>(std::piecewise_construct_t const&, std::tuple<clang::Decl*&&>&&, std::tuple<clang::FunctionDecl*&&>&&) /usr/include/llvm/ADT/SmallVector.h:569:14
 #7 0x00007c79b7886ed8 std::pair<clang::Decl*, clang::FunctionDecl*>& llvm::SmallVectorImpl<std::pair<clang::Decl*, clang::FunctionDecl*>>::emplace_back<std::piecewise_construct_t const&, std::tuple<clang::Decl*&&>, std::tuple<clang::FunctionDecl*&&>>(std::piecewise_construct_t const&, std::tuple<clang::Decl*&&>&&, std::tuple<clang::FunctionDecl*&&>&&) /usr/include/llvm/ADT/SmallVector.h:952:38
 #8 0x00007c79b7886ed8 std::pair<clang::Decl*, clang::FunctionDecl*>& llvm::SmallVectorImpl<std::pair<clang::Decl*, clang::FunctionDecl*>>::emplace_back<std::piecewise_construct_t const&, std::tuple<clang::Decl*&&>, std::tuple<clang::FunctionDecl*&&>>(std::piecewise_construct_t const&, std::tuple<clang::Decl*&&>&&, std::tuple<clang::FunctionDecl*&&>&&) /usr/include/llvm/ADT/SmallVector.h:950:0
 #9 0x00007c79b7886ed8 std::pair<std::pair<clang::Decl*, clang::FunctionDecl*>*, bool> llvm::MapVector<clang::Decl*, clang::FunctionDecl*, llvm::SmallDenseMap<clang::Decl*, unsigned int, 4u, llvm::DenseMapInfo<clang::Decl*, void>, llvm::detail::DenseMapPair<clang::Decl*, unsigned int>>, llvm::SmallVector<std::pair<clang::Decl*, clang::FunctionDecl*>, 4u>>::try_emplace<clang::FunctionDecl*>(clang::Decl*&&, clang::FunctionDecl*&&) /usr/include/llvm/ADT/MapVector.h:133:26
#10 0x00007c79b7886ed8 llvm::MapVector<clang::Decl*, clang::FunctionDecl*, llvm::SmallDenseMap<clang::Decl*, unsigned int, 4u, llvm::DenseMapInfo<clang::Decl*, void>, llvm::detail::DenseMapPair<clang::Decl*, unsigned int>>, llvm::SmallVector<std::pair<clang::Decl*, clang::FunctionDecl*>, 4u>>::insert(std::pair<clang::Decl*, clang::FunctionDecl*>&&) /usr/include/llvm/ADT/MapVector.h:145:23
#11 0x00007c79b7886ed8 void clang::ASTDeclReader::attachPreviousDeclImpl<clang::FunctionDecl>(clang::ASTReader&, clang::Redeclarable<clang::FunctionDecl>*, clang::Decl*, clang::Decl*) /usr/src/debug/clang/clang-18.1.8.src/lib/Serialization/ASTReaderDecl.cpp:3660:48
#12 0x00007c79b78a2b71 clang::ASTReader::finishPendingActions() /usr/src/debug/clang/clang-18.1.8.src/lib/Serialization/ASTReader.cpp:9571:28
#13 0x00007c79b78ade9e clang::ASTReader::FinishedDeserializing() /usr/src/debug/clang/clang-18.1.8.src/lib/Serialization/ASTReader.cpp:10090:3
#14 0x00007c79b78ade9e clang::ExternalASTSource::Deserializing::~Deserializing() /usr/src/debug/clang/clang-18.1.8.src/include/clang/AST/ExternalASTSource.h:86:36
#15 0x00007c79b78ade9e clang::ASTReader::FindExternalVisibleDeclsByName(clang::DeclContext const*, clang::DeclarationName) /usr/src/debug/clang/clang-18.1.8.src/lib/Serialization/ASTReader.cpp:7981:1
#16 0x00007c79b6298853 clang::DeclContext::lookup(clang::DeclarationName) const /usr/src/debug/clang/clang-18.1.8.src/lib/AST/DeclBase.cpp:1822:60
#17 0x00007c79b6c663ca LookupDirect /usr/src/debug/clang/clang-18.1.8.src/lib/Sema/SemaLookup.cpp:1124:23
#18 0x00007c79b6c698de clang::Sema::LookupQualifiedName(clang::LookupResult&, clang::DeclContext*, bool) /usr/src/debug/clang/clang-18.1.8.src/lib/Sema/SemaLookup.cpp:2448:3
#19 0x00007c79b6a4823e clang::Sema::ActOnStartNamespaceDef(clang::Scope*, clang::SourceLocation, clang::SourceLocation, clang::SourceLocation, clang::IdentifierInfo*, clang::SourceLocation, clang::ParsedAttributesView const&, clang::UsingDirectiveDecl*&, bool) /usr/src/debug/clang/clang-18.1.8.src/lib/Sema/SemaDeclCXX.cpp:11658:28
#20 0x00007c79b5fbc4f0 clang::PrettyDeclStackTraceEntry::PrettyDeclStackTraceEntry(clang::ASTContext&, clang::Decl*, clang::SourceLocation, char const*) /usr/src/debug/clang/clang-18.1.8.src/include/clang/AST/PrettyDeclStackTrace.h:38:54
#21 0x00007c79b5fbc4f0 clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/ParseDeclCXX.cpp:236:72
#22 0x00007c79b5fdd00f clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/ParseDecl.cpp:1928:0
#23 0x00007c79b60694cb clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/Parser.cpp:1018:32
#24 0x00007c79b5fbb3ff clang::AttributePool::~AttributePool() /usr/src/debug/clang/clang-18.1.8.src/include/clang/Sema/ParsedAttr.h:705:41
#25 0x00007c79b5fbb3ff clang::ParsedAttributes::~ParsedAttributes() /usr/src/debug/clang/clang-18.1.8.src/include/clang/Sema/ParsedAttr.h:935:7
#26 0x00007c79b5fbb3ff clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::ParsedAttributes&, clang::BalancedDelimiterTracker&) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/ParseDeclCXX.cpp:264:5
#27 0x00007c79b5fbc579 clang::Parser::ParseScope::Exit() /usr/src/debug/clang/clang-18.1.8.src/include/clang/Parse/Parser.h:1161:24
#28 0x00007c79b5fbc579 clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/ParseDeclCXX.cpp:243:22
#29 0x00007c79b5fdd10c clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/ParseDecl.cpp:1940:0
#30 0x00007c79b60694cb clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/Parser.cpp:1018:32
#31 0x00007c79b606a06b clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/Parser.cpp:760:36
#32 0x00007c79b5f8cfb8 clang::ParseAST(clang::Sema&, bool, bool) /usr/src/debug/clang/clang-18.1.8.src/lib/Parse/ParseAST.cpp:162:69
#33 0x00007c79b7a583d1 clang::FrontendAction::Execute() /usr/src/debug/clang/clang-18.1.8.src/lib/Frontend/FrontendAction.cpp:1069:21
#34 0x00007c79b79f9017 llvm::Error::getPtr() const /usr/include/llvm/Support/Error.h:279:0
#35 0x00007c79b79f9017 llvm::Error::operator bool() /usr/include/llvm/Support/Error.h:239:0
#36 0x00007c79b79f9017 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /usr/src/debug/clang/clang-18.1.8.src/lib/Frontend/CompilerInstance.cpp:1057:0
#37 0x00007c79b79f9549 clang::FrontendAction::~FrontendAction() /usr/src/debug/clang/clang-18.1.8.src/lib/Frontend/FrontendAction.cpp:149:0
#38 0x00007c79b79f9549 clang::ASTFrontendAction::~ASTFrontendAction() /usr/src/debug/clang/clang-18.1.8.src/include/clang/Frontend/FrontendAction.h:243:0
#39 0x00007c79b79f9549 clang::GenerateModuleAction::~GenerateModuleAction() /usr/src/debug/clang/clang-18.1.8.src/include/clang/Frontend/FrontendActions.h:116:0
#40 0x00007c79b79f9549 clang::GenerateModuleFromModuleMapAction::~GenerateModuleFromModuleMapAction() /usr/src/debug/clang/clang-18.1.8.src/include/clang/Frontend/FrontendActions.h:142:0
#41 0x00007c79b79f9549 operator() /usr/src/debug/clang/clang-18.1.8.src/lib/Frontend/CompilerInstance.cpp:1278:0
#42 0x00007c79b79f9549 callback_fn<compileModuleImpl(clang::CompilerInstance&, clang::SourceLocation, llvm::StringRef, clang::FrontendInputFile, llvm::StringRef, llvm::StringRef, llvm::function_ref<void(clang::CompilerInstance&)>, llvm::function_ref<void(clang::CompilerInstance&)>)::<lambda()> > /usr/include/llvm/ADT/STLFunctionalExtras.h:45:0
#43 0x00007c79adea8d3a llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/usr/lib/libLLVM.so.18.1+0x6a8d3a)
#44 0x00007c79adea8df0 (/usr/lib/libLLVM.so.18.1+0x6a8df0)
#45 0x00007c79adea87ab (/usr/lib/libLLVM.so.18.1+0x6a87ab)
#46 0x00007c79ad2a339d (/usr/lib/libc.so.6+0x9439d)
#47 0x00007c79ad32849c (/usr/lib/libc.so.6+0x11949c)
clang: error: unable to execute command: Segmentation fault (core dumped)
clang: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 18.1.8
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/test-a7e820.cpp
clang: note: diagnostic msg: /tmp/test-a7e820.cache
clang: note: diagnostic msg: /tmp/test-a7e820.sh
clang: note: diagnostic msg: 

********************
```

</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzsW8ty27jSfhp6g7KKBO8LL2RZyrjKmfiPNPln5wKBloQT3g4AOvYs5tlPAaQokrr5Imfq1EmVYikk2Pi6--tG40IiJV_lAFeWf235NxekUutCXP31XGLb9i-Sgj1fWYHdfOwbyx7f303H8ymSVZJxhQhKqhUSUBZCIVWgtVKltNyxhWcWnq24WlfJiBaZhWdp-rj5uixF8S-gysIzLmUF0sIzRHKGeE7TigFSa0BUELlGCaHflSAULDxBpYBSFBSkBIZkUYn6sn6SSFlQThQwJKocSSp4qUY15Lki9DtiVVZqZOaSPbLs2MKzSgoLzxKeW3g2Gmk8NQILz6iFr81n9uhYePbwIJ-lguwBhCj0Q-b7gRY544oX-WhtuWMcWe7YsdwxopUQkCtUEiFBIFV8hxxZOFSQlSlRYOGwRuJ8EJJAI0GWO5mXkKY8X1nuzSu7oUW-5CvLHUeRZ7ljN7bcqdZN68TzFcpJBrIkFLRiUrFWJ2Rh10b2k23bdkjDmLAl9VhsI8MBd2y5Y_ks6x_3gufKeGhRuznaNhLkx0MhlQCSWTjQrua5snCMLBy1uqQ8qf_e3X37PJLFyIlGjoWv7afQdGrheIvKGaBymMdeLE037knDPWnYow6z90ujWlRg5LjMYX1QbkdMEkZRACzqmGqekTT9BlQV4ppIsNxJlZuwZcYcxifaovwvMH3HiBa5VKhFsXVxE4Pjm4WFZx25hjKxJq6Lt7i8F-NaNKyeFFlW5JY70WwwjUrCheVOaEo0A_WVG6Cphcfam52rsyqnmrybu-5UN3gsOGsVhJw1-r1WMxxhyx17zlY1_9WqNaY_k2JKVNAqVlZy_aATnYWjs8h_vYX8UOcLL9haKNhnobOgC_4xQ69E8WOcs6nuiMK1tni3Iw4UfnAJDyZ-REXVg6pjqck-bVNVlSkcABXoT935sfZDuO1z-tHow0AFL3jqILTm6TfQK4j1cORt6RX-bHrdZmV6Jlq1CanmUR26v4j0M4gU-zqTu9GWSNEvIv0i0luIZFvu2N7yKH4Jj87CK9MmKYrUcqcdin0mZY3vLXLxZEjWG8glfCblQWm9IhJPkFf1pWwE3ObL4qCQTYHWe5KBIjztS7k_ZrCdena6R6HWOGeqDLyqG4JKPD80YXiceiYYDhL6hJdeytaWC4arjuvWMzpDVj2LsY-Xr7-o9E9SiecShDpXLf9Gyni-poy7pYyzjzLa5l0A4_lC9_0VCANRXyJKEbq-F_DIi0rqu80AeAj3MEDG80Ujbyc-vgIDmhJBkqMJv02aJw3YXu3YSwpq4RmDpFpZeFY3br4v9eR-FI3qJvVkfQ6Ck5T_RXT32rob-Fr2iJalrj-CQI8eXrQ1L-6bl-AkdNBeK5j_LnnO5foecsbz1dioKoeT23MBb0DHfujUS1Qt6MHCA2EQwxHQMwMa2A3Ipi-uIX0oase2Y23rDpO9E6inTwpETtLxfDGv1wgbbnRRm0t_n0eTzhJa02g81yG5A8SEZhQYBm318V_tBbaR_I1LnqSgqSmvn38nGewOTpMiV_DUVmj7QoYIY_76-Y_zZRhHjlkfbVXvLTIEOI4i3x2Ca_DXF9Ki-F6Vu0oONBgsgL1Sj9p7Wuw1kbAhYoT11GOzDK7R9-awAQ0ClxJ0ZxDecAH07QjmkJHmq5a3AeFgb5DXowGIOGI99hhR5lct6f8qkvIlB7bLlrrBV5BVqnaTddcXnRr2XXzZryX2vKgf8r3iPCBehN0DSo6p-pLPFRHq983q9A0s-3rOaVHCbiTUMXpX0Ia_Z7p5yyBX2uLClD-v6_aeCAlsrJTgSaVAfuPwozfX6rT9Q_J8VROPP0K35jyrqwwP_vyzZWTgR_1hBfeqU3-ZUG9p95QSoNSzlrNd95_mSjyfuj2sK1o67uPqiyy9JqKTGM-Z_PdpYfK_q83le1tzOafMZbaQOr9bZu_Pg4Vo7XJU_aHRhvffzhaDcvPd5wt29fAX4q36uK8-Y7a9PKp-J9-f1wDDYHtLi2Ef76pFd-y4CbrYbDRuhyLcq-QCO4g9mhw14qaCOGjMcxjjvt4oNEFQAj2nNbb1oRN1tq20LbxBPCXuskeoFvG9WYMxhWD_2vkKwSZvbk1lUkBo-539KI3ZP4F5x9Y17F0XfDDy2NXIwy3w4CXAu8S7zXMQ3Qx2aG5-QEj_-XpIbWbgvYFxuCZx1jxwTVKSUz0TSnnGFQid3r83U9yPyZuBLvz8reHD4ajhh_FRw9dVTzND4uqMVBkE5rouC8xkszPMRa8F_F89zHlmya6TleLhMOfY9Ncwd2KY8-zeMNc7VPI_Psz1jrJoWxA7OG6LRVHewSOkdXHcNcKXkvy7gnu1Z5Hykyj0lHC5WYuc7J92fS5YlcJtVhZCzZU533S-TNiuH5hVt87SiTuoHSO6TKIdG5h6PBrC7s6L3j8_6uEdzxcbtwVmzSDeIu4vuRE_cllvnXAmdEznrF4T3KRroJWCd660bSR3ftadtBQzm_R4W5UMDgDFy9h2ws5a-tScPzM_V6A0fV52_GhelZonFp4ZCfURnTDuh7r_4r6LEkw2bJx44oTQ3s7dQefBvs47XpoUWclTPaOXShcCPT81rutRbuDW9wVHx5NDIK0v_bCvUTjUyPfiU7z7e4j6Y_nnDZwQnYA8ni_2ot69fr5S57AS63bU76gQn1DhE-Sau1Cnz54We2_9BEXkpn7raeLZr9JkJoqs_vWZlEfU2tfu5-no4b6Ozj4dN9nlfOw_FLM47E_qPbzX5iRNE0K_PyxzPVrXstrhdzCw7-Spk4Vcb69UCZ6v9OA_2KZsdLnNy0rNeApHHjt5edns9D0IXWRMzC7waR3inY3d98iJ6xaWO0lJljBS-1rPKM2_U0dLFneb7UqSTp-UIDW_zBZsx51u77QwkIi5pKPARBC5_gq0eATx3Nv0-Frlc7KE9Lk3W96jMGqBv_yQdGBwtOeRNVBvB-jywLHmvdKWdk-aP5QWkuTl0kKS9KQF_SPXxHXjAwe4O0euY8-NWU9M2BPj4siL6UkxjhN7MW3lbLiFoKlFUJWTJAWkCgR1KYBokWUkZ_rmHFYZ5MrEGVqSKtUlUkQLAebVBGBHBJsraNnE3UYqWhKeAkOsMn1KvspJqoVWEtDlo7kGgHj-uJ3sdnpAjyCkBlOnq_rOgogVaN6hpyh4CLzLkl6mPK-eLld51TRZCyAMZQWD1LwOUEj-VN8ysZWmwG64wd174aCvW14oXTYhxskqL6TiFGXS3Nl46R2fWkL3fZXxYjGe_IYWv03R7Mvd3Zf_v_39E5rd3k3naPHFXL7-4xP6Or3_8nVhbd4Sud_3vkkkdXAdfOekbSAApdruwBBRrciX6I9nKiv1X5DqkoQQYduMEe8TQOga3idCrl_rw3N5sv8K0gW7clnsxuQCrpwQuziOY8e-WF850dJz4sRLEmAOtkkMmIVu4Dtx5BLm2Rf8CtvYsyPHdjzs2-7IT_zEs0PiRSQJ7QBbng0Z4elI59lRIVYX5gWlK8fGoedfpCSBVG7elhJX5mWmpFpJy7NTLpXcPqe4SuGqDrRLcxLopnnBBrvocpmZEVuaWzrXuDc619QNENJW1y5vIvyiEunV21-tasA_XuH_BAAA__-HBEIh">