setup-fortran

Set up Fortran compiler toolchains for GitHub Actions. Supports GNU, Intel, LLVM, NVIDIA, AMD, Arm, and LFortran compilers across Linux, macOS, and Windows.

Migration Guide

Migrating from v1 requires only a few changes:

• With Intel compilers, this action sets up the oneAPI environment. Do not re-run environment setup scripts such as setvars.bat or vcvarsall.bat after this action runs. Doing so can cause the PATH variable to exceed character limits on Windows.
• ifx configurations on macOS were previously redirected to ifort. This behavior is no longer supported; ifx on macOS will fail. Remove these configurations from your workflow matrices.
• In 2022, oneAPI release numbers differed from compiler version numbers. For example, oneAPI 2022.1 on Windows installed ifx version 2022.2.0. Compiler versions are now used consistently, so 2022.1 is no longer listed as a supported version. Use 2022.2.0 instead.
• Intel's Fortran-only installer for Windows does not come with a working icx backend, so the preferred C/C++ companion compiler has been changed to cl. If you have hardcoded CC=icx/CXX=icx anywhere in your own workflow, remove these settings and let the action provide the appropriate values.
• The legacy compiler names gcc, intel, intel-classic, and nvidia-hpc remain supported as compatibility aliases. Migrating to the canonical names is recommended.

Usage

- uses: fortran-lang/setup-fortran@v2
  with:
    compiler: <compiler>
    version: <version>

Inputs

Input	Description	Default
compiler	Compiler to install (gfortran, ifx, ifort, nvfortran, aocc, lfortran, flang, armflang)	gfortran
version	Compiler version to install. Enclose the version string in quotation marks (e.g. "2026.1.1" or "0.64.0")	latest
msystem	Windows toolchain environment (native, ucrt64, clang64)	native
cleanup-disk	Free up disk space by removing large pre-installed toolkits during nvfortran setup (true, false)	false
update-environment	Whether to export toolchain environment variables (FC, CC, CXX, FPM_*, F77, F90, FORTRAN_COMPILER) into the runner environment (true, false)	true

For compatibility with fortran-lang/setup-fortran, the legacy names gcc, intel, intel-classic, and nvidia-hpc are accepted as aliases for gfortran, ifx, ifort, and nvfortran, respectively. Aliases do not change based on platform; for example, intel always resolves to ifx. Use of the canonical names is recommended.

Compiler Support

gfortran

Version	ubuntu-24.04	ubuntu-22.04	ubuntu-24.04-arm	ubuntu-22.04-arm	macos-26	macos-26-intel	macos-15	macos-15-intel	macos-14	windows-2025	windows-2022	windows-2025 (ucrt64)	windows-2022 (ucrt64)
latest	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
16	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
15	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
14	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
13	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
12	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
11	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓

---

ifx

Version	ubuntu-24.04	ubuntu-22.04	windows-2025	windows-2022
latest	✓	✓	✓	✓
2026.1.1			✓	✓
2026.1.0			✓	✓
2026.1	✓	✓	✓	✓
2026.0	✓	✓	✓	✓
2025.3.3			✓	✓
2025.3.2			✓	✓
2025.3.1			✓	✓
2025.3.0			✓	✓
2025.3	✓	✓	✓	✓
2025.2.1			✓	✓
2025.2.0			✓	✓
2025.2	✓	✓	✓	✓
2025.1.0			✓	✓
2025.1	✓	✓	✓	✓
2025.0.0			✓	✓
2025.0	✓	✓	✓	✓
2024.2.1			✓	✓
2024.2.0			✓	✓
2024.2	✓	✓	✓	✓
2024.1.0			✓	✓
2024.1	✓	✓	✓	✓
2024.0.2			✓	✓
2024.0.1			✓	✓
2024.0	✓	✓	✓	✓
2023.2.4	✓	✓
2023.2.3	✓	✓
2023.2.2	✓	✓
2023.2.1	✓	✓	✓	✓
2023.2.0	✓	✓	✓	✓
2023.2	✓	✓	✓	✓
2023.1.0	✓	✓	✓	✓
2023.1	✓	✓	✓	✓
2023.0.0	✓	✓
2023.0	✓	✓
2022.3.0			✓	✓
2022.3			✓	✓
2022.2.1	✓	✓
2022.2.0	✓	✓	✓	✓
2022.2	✓	✓	✓	✓
2022.1.0	✓	✓
2022.1	✓	✓
2022.0.2	✓	✓
2022.0.1	✓	✓
2022.0	✓	✓
2021.4.0	✓	✓
2021.4	✓	✓
2021.3.0	✓	✓
2021.3	✓	✓
2021.2.0	✓	✓
2021.2	✓	✓
2021.1.2	✓	✓
2021.1.1	✓	✓
2021.1	✓	✓

In 2022, ifx compiler version numbers differed from oneAPI release numbers. Specify the compiler version here, not the oneAPI release number.

---

ifort

Version	ubuntu-24.04	ubuntu-22.04	macos-26	macos-15	macos-14	macos-26-intel	macos-15-intel	windows-2025	windows-2022
latest	✓	✓	✓	✓	✓	✓	✓	✓	✓
2021.13	✓	✓						✓	✓
2021.12	✓	✓						✓	✓
2021.11	✓	✓						✓	✓
2021.10	✓	✓	✓	✓	✓	✓	✓	✓	✓
2021.9	✓	✓	✓	✓		✓	✓	✓	✓
2021.8	✓	✓	✓	✓		✓	✓
2021.7.1	✓	✓
2021.7	✓	✓						✓	✓
2021.6	✓	✓	✓	✓		✓	✓	✓	✓
2021.5	✓	✓	✓	✓		✓	✓
2021.4	✓	✓
2021.3	✓	✓	✓	✓		✓	✓
2021.2	✓	✓	✓	✓		✓	✓
2021.1.2	✓	✓
2021.1	✓	✓	✓	✓		✓	✓

Intel ships ifort for macOS as x86_64 binaries. On ARM64 runners they run under Rosetta 2, which the action verifies (and installs if missing) before installation. To keep companion C/C++ objects linkable there, the action exports CFLAGS, CXXFLAGS, and LDFLAGS with -arch x86_64.

---

nvfortran

Version	ubuntu-24.04	ubuntu-22.04	ubuntu-24.04-arm	ubuntu-22.04-arm
latest	✓	✓	✓	✓
26.5	✓	✓	✓	✓
26.3	✓	✓	✓	✓
26.1	✓	✓	✓	✓
25.11	✓	✓	✓	✓
25.9	✓	✓	✓	✓
25.7	✓	✓	✓	✓
25.5	✓	✓	✓	✓
25.3	✓	✓	✓	✓
25.1	✓	✓	✓	✓
24.11	✓	✓	✓	✓
24.9	✓	✓	✓	✓
24.7	✓	✓	✓	✓
24.5	✓	✓	✓	✓
24.3	✓	✓	✓	✓
24.1	✓	✓	✓	✓
23.11	✓	✓	✓	✓
23.9	✓	✓	✓	✓
23.7	✓	✓	✓	✓
23.5	✓	✓	✓	✓
23.3	✓	✓	✓	✓
23.1	✓	✓	✓	✓
22.11	✓	✓	✓	✓
22.9	✓	✓	✓	✓
22.7	✓	✓	✓	✓
22.5	✓	✓	✓	✓
22.3	✓	✓	✓	✓
22.2	✓	✓	✓	✓
22.1	✓	✓	✓	✓
21.11	✓	✓	✓	✓
21.9	✓	✓	✓	✓
21.7	✓	✓	✓	✓
21.5	✓	✓	✓	✓
21.3	✓	✓	✓	✓
21.2	✓	✓	✓	✓
21.1	✓	✓	✓	✓
20.11	✓	✓	✓	✓
20.9	✓	✓	✓	✓
20.7	✓	✓	✓	✓

---

aocc

Version	ubuntu-24.04	ubuntu-22.04
latest	✓	✓
5.2	✓	✓
5.1	✓	✓
5.0	✓	✓
4.2	✓	✓
4.1	✓	✓

---

lfortran

Version	ubuntu-24.04	ubuntu-22.04	ubuntu-24.04-arm	ubuntu-22.04-arm	macos-26	macos-26-intel	macos-15	macos-15-intel	macos-14	windows-2025	windows-2022	windows-2025 (ucrt64)	windows-2022 (ucrt64)	windows-2025 (clang64)	windows-2022 (clang64)
latest	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
0.66.0	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
0.65.0	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
0.64.0	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
0.63.0	✓	✓			✓	✓	✓	✓	✓	✓	✓
0.62.0	✓	✓			✓	✓	✓	✓	✓	✓	✓
0.61.0	✓	✓			✓	✓	✓	✓	✓	✓	✓
0.60.0	✓	✓			✓	✓	✓	✓	✓	✓	✓
0.59.0	✓	✓			✓	✓	✓	✓	✓	✓	✓
0.58.0	✓	✓			✓	✓	✓	✓	✓	✓	✓
0.57.0	✓	✓			✓	✓	✓	✓	✓	✓	✓

---

flang (LLVM Flang)

Version	ubuntu-24.04	ubuntu-22.04	ubuntu-24.04-arm	ubuntu-22.04-arm	macos-26	macos-26-intel	macos-15	macos-15-intel	macos-14	windows-2025	windows-2022	windows-11-arm	windows-2025 (ucrt64)	windows-2022 (ucrt64)	windows-2025 (clang64)	windows-2022 (clang64)
latest	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
23	✓		✓							✓	✓	✓
22	✓	✓	✓	✓						✓	✓	✓
21	✓	✓	✓	✓	✓		✓					✓
20	✓	✓	✓	✓	✓		✓					✓
19	✓	✓	✓	✓	✓	✓	✓	✓
18	✓	✓	✓	✓
17	✓	✓	✓	✓
16		✓

Specific patch versions (e.g. 21.1.6) are supported on macOS and native Windows runners and validated against available GitHub releases. Patch versions are not individually tested.

---

armflang (Arm Toolchain for Linux)

Version	ubuntu-24.04-arm	ubuntu-22.04-arm
latest	✓	✓
23.1	✓	✓
22.1	✓	✓
21.1	✓	✓
20.1	✓	✓

---

Examples

Basic Usage

steps:
  - uses: actions/checkout@v7
  - uses: fortran-lang/setup-fortran@v2
  - run: ${{ env.FC }} hello.f90

If omitted, compiler defaults to gfortran and version to the latest supported version for the platform.

Specific Version

- uses: fortran-lang/setup-fortran@v2
  with:
    compiler: lfortran
    version: "0.66.0"

Matrix Build

strategy:
  matrix:
    os: [ubuntu-latest, macos-latest, windows-latest]
    toolchain:
      - { compiler: gfortran, version: "15" }
      - { compiler: ifx, version: "2026.1" }
      - { compiler: lfortran, version: "0.66.0" }
    exclude:
      - os: macos-latest
        toolchain: { compiler: ifx, version: "2026.1" }
    include:
      - os: windows-11-arm
        toolchain: { compiler: flang, version: "22" }
jobs:
  test:
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v7
      - uses: fortran-lang/setup-fortran@v2
        with:
          compiler: ${{ matrix.toolchain.compiler }}
          version: ${{ matrix.toolchain.version }}
      - run: ${{ env.FC }} hello.f90

Windows with MSYS2

- uses: fortran-lang/setup-fortran@v2
  with:
    compiler: lfortran
    msystem: ucrt64

Outputs

Output	Description
version	Resolved version of the installed compiler
fc	Command or path to the Fortran compiler
cc	Command or path to the C compiler
cxx	Command or path to the C++ compiler

Environment Variables

Variable	Description
FC	Command or path to the Fortran compiler
CC	Command or path to the C compiler
CXX	Command or path to the C++ compiler
FPM_FC	Command or path to the Fortran compiler for fpm
FPM_CC	Command or path to the C compiler for fpm
FPM_CXX	Command or path to the C++ compiler for fpm
F77	Command or path to the Fortran compiler (alias for FC)
F90	Command or path to the Fortran compiler (alias for FC)

Development

Requires Node.js 24 or newer (.nvmrc pins the version CI uses).

Install dependencies with npm ci.

Run npm run all to format and lint the source, run unit tests, bundle the action into dist, and run the smoke tests.

Commit changes to dist together with the source changes, as GitHub Actions executes the bundled code from this directory.

Maintenance

Adding a New Version

1. Add the version to SUPPORTED_VERSIONS in the respective installation script (latest first).
2. Add the version to the CI matrix for that compiler.
3. Update the README.
4. Run npm run all — it will fail if the version isn't tested or documented.

Compilers have separate installation scripts for each platform they support.

Reporting Issues

Report bugs and feature requests in the issue tracker.

License

Apache-2.0