Arch Linux User Repository

Thank you very much for incorporating the lld-linker changes into the latest version! I really appreciate it.

I can confirm that @LeoTolstoi and @krystophny have correctly reported the problem with this package when attempting to compile it on CachyOS. I get the same result.

I tried the PKGBUILD fixes from @krystophny on both CachyOS and Arch. I can confirm that they work properly on CachyOS, and do not interfere with correct operation on Arch.

The reason for the fixes is to allow the LLVM libraries to be compiled to a more optimizable form, with more information in them than a normal linker can handle. This is what CachyOS does, and is why the current PKGBUILD does not work on CachyOS. Using the modified PKGBUILD on Arch does not change the way the Arch build works, however. It still uses the normal object files.

Consequently, I would like to request that the fixes be applied. Here they in diff form.

--- PKGBUILD-   2026-02-02 14:36:44.365544751 -0800
+++ PKGBUILD+   2026-02-02 14:42:25.624466639 -0800
@@ -6,8 +6,8 @@
 url="https://mlir.llvm.org/"
 license=("Apache-2.0 WITH LLVM-exception")
 depends=("llvm-libs")
-makedepends=("cmake" "llvm>=${pkgver%%.*}")
-options=(!lto !debug)
+makedepends=("cmake" "llvm>=${pkgver%%.*}" "lld")
+options=(!lto)
 _source_base=https://github.com/llvm/llvm-project/releases/download/llvmorg-$pkgver
 source=($_source_base/mlir-$pkgver.src.tar.xz{,.sig}
         $_source_base/cmake-$pkgver.src.tar.xz{,.sig})
@@ -32,6 +32,10 @@
 build() {
   cp -r cmake{-$pkgver.src,}
   cd mlir-${pkgver}.src
+
+  export CXXFLAGS="${CXXFLAGS} -Wp,-U_GLIBCXX_ASSERTIONS"
+  export LDFLAGS="${LDFLAGS} -Wl,--as-needed"
+
   cmake \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=/usr \
@@ -41,6 +45,8 @@
     -DLLVM_BUILD_TOOLS=ON \
     -DLLVM_BUILD_UTILS=ON \
     -DLLVM_ENABLE_PIC=ON \
+    -DLLVM_TABLEGEN=/usr/bin/llvm-tblgen \
+    -DLLVM_USE_LINKER=lld \
     -B build -S .
   cmake --build build
 }

thank!

done

I needed a small adjustment to get rid of No such file or directory #include "mlir/Dialect/Vector/Transforms/VectorTransformsEnums.h.inc"

diff --git a/PKGBUILD b/PKGBUILD
index 55f2e00..4dacc41 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -24,6 +24,8 @@ prepare() {
   cd mlir-${pkgver}.src/
   # /usr/bin/ld: cannot find -lLLVMCodeGenTypes: No such file or directory
   sed -i 's|LLVM_LINK_COMPONENTS|IGNORE_THAT|g' tools/mlir-tblgen/CMakeLists.txt
+  # https://github.com/llvm/llvm-project/issues/160896
+  sed -i '13iMLIRVectorTransformsIncGen' lib/Dialect/Vector/IR/CMakeLists.txt
 }

 build() {

Please bump version and change linker to lld in order to support also CachyOS (should still work on vanilla Arch).

New PKGBUILD:

pkgname=mlir
pkgver=21.1.5
pkgrel=1
pkgdesc="Multi-Level IR Compiler Framework for LLVM"
arch=('x86_64')
url="https://mlir.llvm.org/"
license=("Apache-2.0 WITH LLVM-exception")
depends=("llvm-libs")
makedepends=("cmake" "llvm>=${pkgver%%.*}" "lld")
options=(!lto)
_source_base=https://github.com/llvm/llvm-project/releases/download/llvmorg-$pkgver
source=($_source_base/mlir-$pkgver.src.tar.xz{,.sig}
        $_source_base/cmake-$pkgver.src.tar.xz{,.sig})
sha256sums=('136897b12083c42a6742a2ca62acc7cf42b0c181edebebd3b7366eeb41d3a805'
            'SKIP'
            '48013d5714a96419bf993a2e5e4c5827377e8cf9c565070731fb2305d50d9511'
            'SKIP')
validpgpkeys=('474E22316ABF4785A88C6E8EA2C794A986419D8A'  # Tom Stellard <tstellar@redhat.com>
              'D574BD5D1D0E98895E3BF90044F2485E45D59042'  # Tobias Hieta <tobias@hieta.se>
              'FFB3368980F3E6BB5737145A316C56D064CACBA5'  # Douglas Yung <douglas.yung@sony.com>
              '71046D1E9C6656BDD61171873E83BABF4A4F9E85') # Cullen Rhodes <cullen.rhodes@arm.com>

prepare() {
  cd mlir-${pkgver}.src/
  # /usr/bin/ld: cannot find -lLLVMCodeGenTypes: No such file or directory
  sed -i 's|LLVM_LINK_COMPONENTS|IGNORE_THAT|g' tools/mlir-tblgen/CMakeLists.txt
}

build() {
  cp -r cmake{-$pkgver.src,}
  cd mlir-${pkgver}.src

  export CXXFLAGS="${CXXFLAGS} -Wp,-U_GLIBCXX_ASSERTIONS"
  export LDFLAGS="${LDFLAGS} -Wl,--as-needed"

  cmake \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_INSTALL_PREFIX=/usr \
    -DLLVM_LINK_LLVM_DYLIB=ON \
    -DLLVM_BUILD_LLVM_DYLIB=ON \
    -DMLIR_LINK_MLIR_DYLIB=ON \
    -DLLVM_BUILD_TOOLS=ON \
    -DLLVM_BUILD_UTILS=ON \
    -DLLVM_ENABLE_PIC=ON \
    -DLLVM_TABLEGEN=/usr/bin/llvm-tblgen \
    -DLLVM_USE_LINKER=lld \
    -B build -S .
  cmake --build build
}

package() {
  cd mlir-${pkgver}.src
  DESTDIR="${pkgdir}" cmake --build build --target install
}

This version is broken, see https://github.com/llvm/llvm-project/issues/160896.

What wanghaoran said: Missing keys. Even installing the key doesn't help.

missing validpgpkeys '71046D1E9C6656BDD61171873E83BABF4A4F9E85'# Cullen Rhodes cullen.rhodes@arm.com , so is flang

maybe try to uninstall any previous version of mlir first, or get rid of any cache/build files, also it takes a lot of memory if you have -jx MAKEFLAGS set in makepkg.conf