Install ¶

1 Requirements ¶

A Fortran 2018 compiler (gfortran 13+ is what CI and pixi pin)
fpm for the library and tests
fypp to regenerate capnp_endian / capnp_message from .fypp sources
The Cap’n Proto capnp tool when compiling schemas or regenerating fixtures

Optional interop tier:

meson, ninja, a C/C++ toolchain, cmocka
libcapnp / libcapnp-rpc for the live C++ RPC peer test

2 fpm ¶

$ git clone https://github.com/HaoZeke/capnp-fortran.git
$ cd capnp-fortran
$ fpm build
$ fpm test

The package name in fpm.toml is capnp; the executable is capnpc-fortran.

3 pixi (recommended)¶

pixi.toml pins gfortran, fpm, fypp, and capnproto on linux-64:

$ pixi install
$ pixi run gen      # fypp → src/*.f90 (commit if templates change)
$ pixi run build
$ pixi run test

Environments:

Feature	Purpose
default	library + tests
interop	meson + cmocka + C++ for golden master / C++ peer
docs	Sphinx + emacs ox-rst export

4 Interop suite ¶

$ git clone --depth 1 https://github.com/opensourcerouting/c-capnproto third_party/c-capnproto
$ pixi run -e interop meson setup build-interop .
$ pixi run -e interop meson compile -C build-interop
$ pixi run -e interop meson test -C build-interop -v

When libcapnp-rpc is available, meson also builds the Fortran RPC client against a C++ EzRpcServer (schema adder.capnp). Details: Interop.

5 Building documentation ¶

$ pixi run -e docs docs
# HTML under docs/build/

Live site: https://capnp-fortran.rgoswami.me (Cloudflare Pages via the Documentation workflow).

6 Using the library from another fpm project ¶

Add a dependency on this repository (or the fpm registry package capnp once published), then:

use capnp

Generated schema modules are ordinary Fortran sources you compile alongside your program after running capnpc-fortran.

Install¶

1 Requirements¶

2 fpm¶