On Thu, 30 Jun 2022 11:00:03 +0200 Hartmut Goebel
wrote:
> The rebar-build-system I created was published just a few weeks ago.
> Anyhow, I'm not a Erlang/OTP user, so this build-system might still need
> improvement. Any help on this is welcome.
Hi Hartmut,
Good News!
I found out what environment variable we need to set in order for Guix to find
Erlang libraries:
It's ERL_LIBS that needs to be set in order for Erlang to find
installed libraries in /guix/store/.../lib/erlang/lib/
Here's an example of what Nix does:
https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/beam-modules/hex/default.nix#L21
I tested this with a guix shell and erlang-jsx:
https://issues.guix.gnu.org/58458
All I did was enter an erlang repl (erl) and run the following code:
λ guix shell -D guix --pure
hint: Consider passing the `--check' option once to make sure your shell does
not clobber environment variables.
guix-shell ./pre-inst-env guix shell erlang erlang-jsx --search-paths --pure
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/python.scm
;;; newer than compiled
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/python.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/python.scm
;;; newer than compiled
/home/jgart/.guix-profile/lib/guile/3.0/site-ccache/gnu/packages/python.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/erlang.scm
;;; newer than compiled
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/erlang.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/erlang.scm
;;; newer than compiled
/home/jgart/.guix-profile/lib/guile/3.0/site-ccache/gnu/packages/erlang.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/guix/build-system/rebar.scm
;;; newer than compiled
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/guix/build-system/rebar.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/guix/build-system/rebar.scm
;;; newer than compiled
/home/jgart/.guix-profile/lib/guile/3.0/site-ccache/guix/build-system/rebar.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/entr.scm
;;; newer than compiled
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/entr.go
;;; note: source file
/home/jgart/7a41616f-b6b7-4643-898b-5771ddf02d32-guix/gnu/packages/entr.scm
;;; newer than compiled
/home/jgart/.guix-profile/lib/guile/3.0/site-ccache/gnu/packages/entr.go
;;; Ignore this. This was printed courtesy of the pk macro ;()
;;; (#)
export PATH="/gnu/store/95i56pzs3g1hysaj32c8jzchw5n30fhz-profile/bin"
export XDG_DATA_DIRS="/gnu/store/95i56pzs3g1hysaj32c8jzchw5n30fhz-profile/share"
guix-shell ls /gnu/store/95i56pzs3g1hysaj32c8jzchw5n30fhz-profile/bin
ct_runerl fc-cache fc-list fc-query freetype-config
png-fix-itxt to_erl
dialyzer erlc fc-cat fc-matchfc-scan libpng-config
pngfixtyper
epmd escript fc-conflist fc-pattern fc-validate libpng16-config
run_erl xmlwf
guix-shell erl
bash: erl: command not found
(reverse-i-search)`s': ./pre-inst-env guix shell erlang erlang-jsx
--search-path^C--pure
guix-shell export
ERL_LIBS=/gnu/store/95i56pzs3g1hysaj32c8jzchw5n30fhz-profile/lib/erlang/lib
guix-shell /gnu/store/95i56pzs3g1hysaj32c8jzchw5n30fhz-profile/bin/erl
Erlang/OTP 25 [erts-13.0.4] [source] [64-bit] [smp:4:4] [ds:4:4:10]
[async-threads:1] [jit:ns]
Eshell V13.0.4 (abort with ^G)
1> jsx:decode(<<"{\"library\": \"jsx\", \"awesome\": true}">>, []).
#{<<"awesome">> => true,<<"library">> => <<"jsx">>}
As you can see above we don't need to import anything into the repl
because we just namespace with installed library in order to use it. I
think this may be what erlangers normally do at the repl instead of
importing.
See the erlang-jsx README:
https://github.com/talentdeficit/jsx#to-convert-a-utf8-binary-containing-a-json-string-into-an-erlang-term
I'll try to find the time to add setting this environment variable to
the rebar-build-system, otherwise if you'd like to proceed with adding
it that is also fine by me :)
all best,
jgart