Supported Compilers

The following compilers are currently supported for the develop version of spack-stack. Check the end user release docs for supported compilers for specific releases. New or older versions of the following compilers, or different compilers may or may not work. Note that we have limited resources available for support. Further note that Intel compiler versions are confusing, because the oneAPI version doesn't match the compiler version. We generally refer to the compiler version being the version string in the path to the compiler, e.g, oneapi@2025.3.0 for /apps/oneapi/compiler/2025.3.0/linux/bin/ifx.

Compiler	Versions	Spack compiler identifiers
Intel classic (icc, icpc, ifort)	2021.3.0 to 2021.10.0 *	intel / intel-oneapi-compilers-classic
Intel mixed (icx, icpx, ifort)	2024.1.2 to 2024.2.1	oneapi / intel-oneapi-compilers
Intel LLVM (icx, icpx, ifx)	2025.0.0 to 2025.3.0	oneapi / intel-oneapi-compilers
GNU (gcc, g++, gfortran)	9.2.0 to 13.3.1	gcc
LLVM (clang, clang++, flang(-new))	20.1.x **	clang / llvm
Nvidia HPC SDK (nvcc, nvc++, nvfortran)	12.6 (Nvidia HPC SDK 25.1) ***	nvhpc

* We have noted problems on some - not all - platforms with intel@2021.5.0 in spack-stack-1.7.0. These issues went away when using a different version of the compiler (anything between 2021.3.0 and 2021.11.0). It is therefore recommended to avoid using intel@2021.5.0 unless it is the only option.

** Experimental, NEPTUNE standalone environment only).

*** Support for Nvidia compilers is experimental and limited to a subset of packages. Please refer to the tier2 site config here.