diff --git a/pkgs/development/compilers/llvm/git/clang/default.nix b/pkgs/development/compilers/llvm/git/clang/default.nix
index 01b33c540ca2..1e777c6132e4 100644
--- a/pkgs/development/compilers/llvm/git/clang/default.nix
+++ b/pkgs/development/compilers/llvm/git/clang/default.nix
@@ -70,9 +70,6 @@ let
     postInstall = ''
       ln -sv $out/bin/clang $out/bin/cpp
 
-      mkdir -p $lib/lib/clang
-      mv $lib/lib/${lib.versions.major version} $lib/lib/clang/${lib.versions.major version}
-
       # Move libclang to 'lib' output
       moveToOutput "lib/libclang.*" "$lib"
       moveToOutput "lib/libclang-cpp.*" "$lib"
diff --git a/pkgs/development/compilers/llvm/git/clang/gnu-install-dirs.patch b/pkgs/development/compilers/llvm/git/clang/gnu-install-dirs.patch
index cc8737f35343..9517df973ad0 100644
--- a/pkgs/development/compilers/llvm/git/clang/gnu-install-dirs.patch
+++ b/pkgs/development/compilers/llvm/git/clang/gnu-install-dirs.patch
@@ -1,30 +1,3 @@
-diff --git a/CMakeLists.txt b/CMakeLists.txt
-index f7936d72e088..a362fa49b534 100644
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -31,7 +31,21 @@ if(CLANG_BUILT_STANDALONE)
-   find_package(LLVM REQUIRED HINTS "${LLVM_CMAKE_DIR}")
-   list(APPEND CMAKE_MODULE_PATH "${LLVM_DIR}")
- 
--  # Turn into CACHE PATHs for overwritting
-+  # We can't check LLVM_CONFIG here, because find_package(LLVM ...) also sets
-+  # LLVM_CONFIG.
-+  if (NOT LLVM_CONFIG_FOUND)
-+    # Pull values from LLVMConfig.cmake.  We can drop this once the llvm-config
-+    # path is removed.
-+    set(INCLUDE_DIRS ${LLVM_INCLUDE_DIRS})
-+    set(LLVM_OBJ_DIR "${LLVM_BINARY_DIR}")
-+    # N.B. this is just a default value, the CACHE PATHs below can be overriden.
-+    set(MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../llvm")
-+    set(TOOLS_BINARY_DIR "${LLVM_TOOLS_BINARY_DIR}")
-+    set(LIBRARY_DIR "${LLVM_LIBRARY_DIR}")
-+  else()
-+    set(INCLUDE_DIRS "${LLVM_BINARY_DIR}/include" "${MAIN_INCLUDE_DIR}")
-+  endif()
-+
-   set(LLVM_INCLUDE_DIRS ${LLVM_INCLUDE_DIRS} CACHE PATH "Path to llvm/include and any other header dirs needed")
-   set(LLVM_BINARY_DIR "${LLVM_BINARY_DIR}" CACHE PATH "Path to LLVM build tree")
-   set(LLVM_MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../llvm" CACHE PATH "Path to LLVM source tree")
 diff --git a/cmake/modules/AddClang.cmake b/cmake/modules/AddClang.cmake
 index 75b0080f6715..c895b884cd27 100644
 --- a/cmake/modules/AddClang.cmake
@@ -48,7 +21,7 @@ index f2b0c5cddcbb..52f37fc368ce 100644
  add_header_target("utility-resource-headers" ${utility_files})
  
  get_clang_resource_dir(header_install_dir SUBDIR include)
-+set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${CLANG_VERSION_MAJOR}/include)
++set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION_MAJOR}/include)
  
  #############################################################
  # Install rules for the catch-all clang-resource-headers target
diff --git a/pkgs/development/compilers/llvm/git/compiler-rt/default.nix b/pkgs/development/compilers/llvm/git/compiler-rt/default.nix
index 51f4e95ef2b5..f51316beb570 100644
--- a/pkgs/development/compilers/llvm/git/compiler-rt/default.nix
+++ b/pkgs/development/compilers/llvm/git/compiler-rt/default.nix
@@ -87,12 +87,9 @@ stdenv.mkDerivation {
 
   patches = [
     ./X86-support-extension.patch # Add support for i486 i586 i686 by reusing i386 config
-    ./gnu-install-dirs.patch
     # ld-wrapper dislikes `-rpath-link //nix/store`, so we normalize away the
     # extra `/`.
     ./normalize-var.patch
-    # Prevent a compilation error on darwin
-    ./darwin-targetconditionals.patch
     # See: https://github.com/NixOS/nixpkgs/pull/186575
     ../../common/compiler-rt/darwin-plistbuddy-workaround.patch
     # See: https://github.com/NixOS/nixpkgs/pull/194634#discussion_r999829893
@@ -111,6 +108,8 @@ stdenv.mkDerivation {
     substituteInPlace cmake/config-ix.cmake \
       --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
   '' + lib.optionalString (useLLVM && !haveLibc) ''
+    substituteInPlace lib/builtins/aarch64/sme-libc-routines.c \
+      --replace "<stdlib.h>" "<stddef.h>"
     substituteInPlace lib/builtins/int_util.c \
       --replace "#include <stdlib.h>" ""
     substituteInPlace lib/builtins/clear_cache.c \
diff --git a/pkgs/development/compilers/llvm/git/compiler-rt/gnu-install-dirs.patch b/pkgs/development/compilers/llvm/git/compiler-rt/gnu-install-dirs.patch
deleted file mode 100644
index f3b1f63a7d71..000000000000
--- a/pkgs/development/compilers/llvm/git/compiler-rt/gnu-install-dirs.patch
+++ /dev/null
@@ -1,20 +0,0 @@
-diff --git a/cmake/base-config-ix.cmake b/cmake/base-config-ix.cmake
-index 8a6219568b3f..30ee68a47ccf 100644
---- a/cmake/base-config-ix.cmake
-+++ b/cmake/base-config-ix.cmake
-@@ -100,13 +100,13 @@ endif()
- if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-   set(COMPILER_RT_OUTPUT_LIBRARY_DIR
-     ${COMPILER_RT_OUTPUT_DIR}/lib)
--  extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" lib)
-+  extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_LIBDIR}")
-   set(COMPILER_RT_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
-     "Path where built compiler-rt libraries should be installed.")
- else(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-   set(COMPILER_RT_OUTPUT_LIBRARY_DIR
-     ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
--  extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "lib/${COMPILER_RT_OS_DIR}")
-+  extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_LIBDIR}/${COMPILER_RT_OS_DIR}")
-   set(COMPILER_RT_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
-     "Path where built compiler-rt libraries should be installed.")
- endif()
diff --git a/pkgs/development/compilers/llvm/git/default.nix b/pkgs/development/compilers/llvm/git/default.nix
index 6ebb2ea9fcc2..80cff85372d0 100644
--- a/pkgs/development/compilers/llvm/git/default.nix
+++ b/pkgs/development/compilers/llvm/git/default.nix
@@ -17,15 +17,20 @@
     else pkgs.bintools
 , darwin
 # LLVM release information; specify one of these but not both:
-, gitRelease ? null
+, gitRelease ? {
+    version = "19.0.0-git";
+    rev = "65058a8d732c3c41664a4dad1a1ae2a504d5c98e";
+    rev-version = "19.0.0-unstable-2024-03-16";
+    sha256 = "sha256-xV33kx/8OZ2KLtaz25RmudDrlIX7nScauTykf87jyTE=";
+}
   # i.e.:
   # {
   #   version = /* i.e. "15.0.0" */;
   #   rev = /* commit SHA */;
-  #   rev-version = /* human readable version; i.e. "unstable-2022-26-07" */;
+  #   rev-version = /* human readable version; i.e. "15.0.0-unstable-2022-07-26" */;
   #   sha256 = /* checksum for this release, can omit if specifying your own `monorepoSrc` */;
   # }
-, officialRelease ? { version = "18.1.0-rc4"; sha256 = "sha256-fVpwewbjoPMPslIEZ+WAtaQ+YKc0XWGl8EbP/TbQb8o="; }
+, officialRelease ? null
   # i.e.:
   # {
   #   version = /* i.e. "15.0.0" */;
diff --git a/pkgs/development/compilers/llvm/git/libcxx/default.nix b/pkgs/development/compilers/llvm/git/libcxx/default.nix
index 4e3404dbe194..d6c304c0b476 100644
--- a/pkgs/development/compilers/llvm/git/libcxx/default.nix
+++ b/pkgs/development/compilers/llvm/git/libcxx/default.nix
@@ -1,5 +1,5 @@
 { lib, stdenv, llvm_meta
-, monorepoSrc, runCommand, fetchpatch
+, monorepoSrc, runCommand
 , cmake, lndir, ninja, python3, fixDarwinDylibNames, version
 , cxxabi ? if stdenv.hostPlatform.isFreeBSD then libcxxrt else null
 , libcxxrt, libunwind
@@ -19,11 +19,11 @@ let
   # Note: useLLVM is likely false for Darwin but true under pkgsLLVM
   useLLVM = stdenv.hostPlatform.useLLVM or false;
 
-  cxxabiCMakeFlags = lib.optionals (useLLVM && !stdenv.hostPlatform.isWasm) [
-    "-DLIBCXXABI_USE_COMPILER_RT=ON"
-    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
-  ] ++ lib.optionals (lib.versionAtLeast version "18" && !(useLLVM && !stdenv.hostPlatform.isWasm)) [
+  cxxabiCMakeFlags = [
     "-DLIBCXXABI_USE_LLVM_UNWINDER=OFF"
+  ] ++ lib.optionals (useLLVM && !stdenv.hostPlatform.isWasm) [
+    "-DLIBCXXABI_ADDITIONAL_LIBRARIES=unwind"
+    "-DLIBCXXABI_USE_COMPILER_RT=ON"
   ] ++ lib.optionals stdenv.hostPlatform.isWasm [
     "-DLIBCXXABI_ENABLE_THREADS=OFF"
     "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
@@ -87,18 +87,6 @@ stdenv.mkDerivation rec {
   patches = lib.optionals (stdenv.isDarwin && lib.versionOlder stdenv.hostPlatform.darwinMinVersion "10.13") [
     # https://github.com/llvm/llvm-project/issues/64226
     ./0001-darwin-10.12-mbstate_t-fix.patch
-  ] ++ lib.optionals (cxxabi == null && lib.versionAtLeast version "18") [
-    # Allow building libcxxabi alone when using LLVM unwinder
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/77610dd10454e87bb387040d2b51100a17ac5755.patch";
-      revert = true;
-      hash = "sha256-jFbC3vBY3nKfjknJ7UzaPyoy0iSYdD3+jUmOFeOaVcA=";
-    })
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/48e5b5ea92674ded69b998cf35724d9012c0f57d.patch";
-      revert = true;
-      hash = "sha256-WN63L4T3GxVozPZb6kx21AgNe4rwwSUOeeryIGsvQYY=";
-    })
   ];
 
   postPatch = ''
diff --git a/pkgs/development/compilers/llvm/git/libunwind/default.nix b/pkgs/development/compilers/llvm/git/libunwind/default.nix
index a3c8e2594f5a..e67823ffb85c 100644
--- a/pkgs/development/compilers/llvm/git/libunwind/default.nix
+++ b/pkgs/development/compilers/llvm/git/libunwind/default.nix
@@ -27,15 +27,6 @@ stdenv.mkDerivation rec {
 
   sourceRoot = "${src.name}/runtimes";
 
-  prePatch = ''
-    cd ../${pname}
-    chmod -R u+w .
-  '';
-
-  postPatch = ''
-    cd ../runtimes
-  '';
-
   postInstall = lib.optionalString (enableShared && !stdenv.hostPlatform.isDarwin) ''
     # libcxxabi wants to link to libunwind_shared.so (?).
     ln -s $out/lib/libunwind.so $out/lib/libunwind_shared.so
diff --git a/pkgs/development/compilers/llvm/git/lld/default.nix b/pkgs/development/compilers/llvm/git/lld/default.nix
index cc18aee76a44..24ff0933dd1d 100644
--- a/pkgs/development/compilers/llvm/git/lld/default.nix
+++ b/pkgs/development/compilers/llvm/git/lld/default.nix
@@ -24,13 +24,13 @@ stdenv.mkDerivation rec {
 
   sourceRoot = "${src.name}/${pname}";
 
+  nativeBuildInputs = [ cmake ninja ];
+  buildInputs = [ libllvm libxml2 ];
+
   patches = [
     ./gnu-install-dirs.patch
   ];
 
-  nativeBuildInputs = [ cmake ninja ];
-  buildInputs = [ libllvm libxml2 ];
-
   cmakeFlags = [
     "-DLLD_INSTALL_PACKAGE_DIR=${placeholder "dev"}/lib/cmake/lld"
   ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
diff --git a/pkgs/development/compilers/llvm/git/lld/gnu-install-dirs.patch b/pkgs/development/compilers/llvm/git/lld/gnu-install-dirs.patch
index 86e76f4a16d8..6c73a240ab6d 100644
--- a/pkgs/development/compilers/llvm/git/lld/gnu-install-dirs.patch
+++ b/pkgs/development/compilers/llvm/git/lld/gnu-install-dirs.patch
@@ -1,34 +1,3 @@
-diff --git a/CMakeLists.txt b/CMakeLists.txt
-index 3d6225646fe6..9b5d0b15af13 100644
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -33,10 +33,22 @@ if(LLD_BUILT_STANDALONE)
-   find_package(LLVM REQUIRED HINTS "${LLVM_CMAKE_DIR}")
-   list(APPEND CMAKE_MODULE_PATH "${LLVM_DIR}")
- 
--  # Turn into CACHE PATHs for overwriting
--  set(LLVM_INCLUDE_DIRS ${LLVM_INCLUDE_DIRS} CACHE PATH "Path to llvm/include and any other header dirs needed")
--  set(LLVM_BINARY_DIR "${LLVM_BINARY_DIR}" CACHE PATH "Path to LLVM build tree")
--  set(LLVM_MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../llvm" CACHE PATH "Path to LLVM source tree")
-+  # We can't check LLVM_CONFIG here, because find_package(LLVM ...) also sets
-+  # LLVM_CONFIG.
-+  if (NOT LLVM_CONFIG_FOUND)
-+    # Pull values from LLVMConfig.cmake.  We can drop this once the llvm-config
-+    # path is removed.
-+    set(INCLUDE_DIRS ${LLVM_INCLUDE_DIRS})
-+    set(LLVM_OBJ_DIR "${LLVM_BINARY_DIR}")
-+    # N.B. this is just a default value, the CACHE PATHs below can be overridden.
-+    set(MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../llvm")
-+  else()
-+    set(INCLUDE_DIRS "${LLVM_BINARY_DIR}/include" "${MAIN_INCLUDE_DIR}")
-+  endif()
-+
-+  set(LLVM_INCLUDE_DIRS ${INCLUDE_DIRS} CACHE PATH "Path to llvm/include and any other header dirs needed")
-+  set(LLVM_BINARY_DIR "${LLVM_OBJ_ROOT}" CACHE PATH "Path to LLVM build tree")
-+  set(LLVM_MAIN_SRC_DIR "${MAIN_SRC_DIR}" CACHE PATH "Path to LLVM source tree")
- 
-   find_program(LLVM_TABLEGEN_EXE "llvm-tblgen" ${LLVM_TOOLS_BINARY_DIR}
-     NO_DEFAULT_PATH)
 diff --git a/cmake/modules/AddLLD.cmake b/cmake/modules/AddLLD.cmake
 index d3924f7243d4..42a7cd62281c 100644
 --- a/cmake/modules/AddLLD.cmake
diff --git a/pkgs/development/compilers/llvm/git/llvm/default.nix b/pkgs/development/compilers/llvm/git/llvm/default.nix
index b8715228ab1c..670171a707f9 100644
--- a/pkgs/development/compilers/llvm/git/llvm/default.nix
+++ b/pkgs/development/compilers/llvm/git/llvm/default.nix
@@ -179,6 +179,10 @@ stdenv.mkDerivation (rec {
     substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
       --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
       --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
+
+    # fails when run in sandbox
+    substituteInPlace unittests/Support/VirtualFileSystemTest.cpp \
+      --replace "PhysicalFileSystemWorkingDirFailure" "DISABLED_PhysicalFileSystemWorkingDirFailure"
   '' + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86) ''
     # This test fails on darwin x86_64 because `sw_vers` reports a different
     # macOS version than what LLVM finds by reading
@@ -382,7 +386,6 @@ stdenv.mkDerivation (rec {
       --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
   ''
   + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
     ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
   ''
   + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
diff --git a/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs-polly.patch b/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs-polly.patch
index 442ebddad3f6..6a359bdbefde 100644
--- a/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs-polly.patch
+++ b/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs-polly.patch
@@ -1,12 +1,6 @@
-This is the one remaining Polly install dirs related change that hasn't made it
-into upstream yet; previously this patch file also included:
-https://reviews.llvm.org/D117541
-
-diff --git a/tools/polly/cmake/polly_macros.cmake b/tools/polly/cmake/polly_macros.cmake
-index 518a09b45a42..bd9d6f5542ad 100644
---- a/tools/polly/cmake/polly_macros.cmake
-+++ b/tools/polly/cmake/polly_macros.cmake
-@@ -45,8 +45,8 @@ macro(add_polly_library name)
+--- a/tools/polly/cmake/polly_macros.cmake	2024-03-15 17:36:20.550893344 -0700
++++ b/tools/polly/cmake/polly_macros.cmake	2024-03-15 17:37:06.277332960 -0700
+@@ -45,8 +45,8 @@
      install(TARGETS ${name}
        COMPONENT ${name}
        EXPORT LLVMExports
diff --git a/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs.patch b/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs.patch
index e2122ebf603d..8b89839490ba 100644
--- a/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs.patch
+++ b/pkgs/development/compilers/llvm/git/llvm/gnu-install-dirs.patch
@@ -40,7 +40,7 @@ index 230620c37027..dd16cab1835e 100644
    if (APPLE)
      set(_install_name_dir INSTALL_NAME_DIR "@rpath")
 -    set(_install_rpath "@loader_path/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
-+    set(_install_rpath "@loader_path/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
++    set(_install_rpath ${extra_libdir})
    elseif(${CMAKE_SYSTEM_NAME} MATCHES "AIX" AND BUILD_SHARED_LIBS)
      # $ORIGIN is not interpreted at link time by aix ld.
      # Since BUILD_SHARED_LIBS is only recommended for use by developers,
@@ -72,8 +72,8 @@ index 230620c37027..dd16cab1835e 100644
 +    # As noted in the differential above, an alternative solution is to have
 +    # all rdeps of nixpkgs' LLVM (that use the AddLLVM.cmake machinery) set
 +    # `CMAKE_INSTALL_RPATH`.
-+    set(_build_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
-+    set(_install_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
++    set(_build_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
++    set(_install_rpath ${extra_libdir})
      if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
        set_property(TARGET ${name} APPEND_STRING PROPERTY
                     LINK_FLAGS " -Wl,-z,origin ")
@@ -86,10 +86,10 @@ index 891c9e6d618c..8d963f3b0069 100644
  
    if( APPLE )
 -    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
-+    set(ocaml_rpath "@executable_path/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
++    set(ocaml_rpath ${LLVM_LIBRARY_DIR})
    elseif( UNIX )
 -    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
-+    set(ocaml_rpath "\\$ORIGIN/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
++    set(ocaml_rpath ${LLVM_LIBRARY_DIR})
    endif()
    list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
  
diff --git a/pkgs/development/compilers/llvm/git/llvm/lit-shell-script-runner-set-dyld-library-path.patch b/pkgs/development/compilers/llvm/git/llvm/lit-shell-script-runner-set-dyld-library-path.patch
index 82b7b21c55fb..e4f049f4b177 100644
--- a/pkgs/development/compilers/llvm/git/llvm/lit-shell-script-runner-set-dyld-library-path.patch
+++ b/pkgs/development/compilers/llvm/git/llvm/lit-shell-script-runner-set-dyld-library-path.patch
@@ -1,17 +1,12 @@
-diff --git a/utils/lit/lit/TestRunner.py b/utils/lit/lit/TestRunner.py
-index 0242e0b75af3..d732011306f7 100644
---- a/utils/lit/lit/TestRunner.py
-+++ b/utils/lit/lit/TestRunner.py
-@@ -1029,6 +1029,12 @@ def executeScript(test, litConfig, tmpBase, commands, cwd):
-             f.write('@echo off\n')
-         f.write('\n@if %ERRORLEVEL% NEQ 0 EXIT\n'.join(commands))
+--- a/utils/lit/lit/TestRunner.py	2024-03-15 17:27:53.170780798 -0700
++++ b/utils/lit/lit/TestRunner.py	2024-03-15 17:28:43.277447791 -0700
+@@ -1183,6 +1183,9 @@
+         f.write("@echo on\n")
+         f.write("\n@if %ERRORLEVEL% NEQ 0 EXIT\n".join(commands))
      else:
-+        # This env var is *purged* when invoking subprocesses so we have to
-+        # manually set it from within the bash script in order for the commands
-+        # in run lines to see this var:
 +        if "DYLD_LIBRARY_PATH" in test.config.environment:
 +            f.write(f'export DYLD_LIBRARY_PATH="{test.config.environment["DYLD_LIBRARY_PATH"]}"\n')
 +
          for i, ln in enumerate(commands):
-             match = re.match(kPdbgRegex, ln)
+             match = re.fullmatch(kPdbgRegex, ln)
              if match:
diff --git a/pkgs/development/compilers/llvm/git/openmp/default.nix b/pkgs/development/compilers/llvm/git/openmp/default.nix
index d51335436ad2..e1c3c2379af2 100644
--- a/pkgs/development/compilers/llvm/git/openmp/default.nix
+++ b/pkgs/development/compilers/llvm/git/openmp/default.nix
@@ -29,7 +29,6 @@ stdenv.mkDerivation rec {
 
   patches = [
     ./fix-find-tool.patch
-    ./gnu-install-dirs.patch
     ./run-lit-directly.patch
   ];
 
diff --git a/pkgs/development/compilers/llvm/git/openmp/gnu-install-dirs.patch b/pkgs/development/compilers/llvm/git/openmp/gnu-install-dirs.patch
deleted file mode 100644
index 0d0d4130c761..000000000000
--- a/pkgs/development/compilers/llvm/git/openmp/gnu-install-dirs.patch
+++ /dev/null
@@ -1,22 +0,0 @@
-diff --git a/CMakeLists.txt b/CMakeLists.txt
-index b6ddbe90516d..311ab1d50e7f 100644
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -29,7 +29,7 @@ if (OPENMP_STANDALONE_BUILD)
-   set(OPENMP_LIBDIR_SUFFIX "" CACHE STRING
-     "Suffix of lib installation directory, e.g. 64 => lib64")
-   # Do not use OPENMP_LIBDIR_SUFFIX directly, use OPENMP_INSTALL_LIBDIR.
--  set(OPENMP_INSTALL_LIBDIR "lib${OPENMP_LIBDIR_SUFFIX}" CACHE STRING
-+  set(OPENMP_INSTALL_LIBDIR "${CMAKE_INSTALL_LIBDIR}${OPENMP_LIBDIR_SUFFIX}" CACHE STRING
-       "Path where built OpenMP libraries should be installed.")
- 
-   # Group test settings.
-@@ -47,7 +47,7 @@ if (OPENMP_STANDALONE_BUILD)
- else()
-   set(OPENMP_ENABLE_WERROR ${LLVM_ENABLE_WERROR})
-   # If building in tree, we honor the same install suffix LLVM uses.
--  set(OPENMP_INSTALL_LIBDIR "lib${LLVM_LIBDIR_SUFFIX}" CACHE STRING
-+  set(OPENMP_INSTALL_LIBDIR "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" CACHE STRING
-       "Path where built OpenMP libraries should be installed.")
- 
-   if (NOT MSVC)