Shachar Itzhaky (Apr 30 2021 at 22:35): Shachar Itzhaky (Apr 30 2021 at 22:35):Here's a mind twister: Installing deps from jscoq.opam installs js_of_ocaml-compiler.3.9.0.
Then, installing elpi.1.13.1 (for coq-elpi) causes OPAM to downgrade js_of_ocaml-compiler to 3.7.1.
Haven't been able to figure out why :confused: Can somebody help?
Emilio Jesús Gallego Arias (Apr 30 2021 at 22:37):Trying blind: ppxlib?
Emilio Jesús Gallego Arias (Apr 30 2021 at 22:40):Now after looking at opam, I think I won :) XD
Shachar Itzhaky (May 01 2021 at 10:11):Yeah I was suspecting ppxlib; but can you explain why? I haven't been able to track the dep chain between ppxlib and js_of_ocaml-compiler.
Emilio Jesús Gallego Arias (May 01 2021 at 12:31):elpi requires ppxlib < 0.15 , however js_of_ocaml-compiler requires ppxlib >= 0.15 ; so this is why opam tries to downgrade jsoo
Emilio Jesús Gallego Arias (May 01 2021 at 12:31):this is due to the ppx 2.0 API
Emilio Jesús Gallego Arias (May 01 2021 at 12:32):eventually elpi should be updated to support ppxlib >= 0.15
Emilio Jesús Gallego Arias (May 01 2021 at 12:33):I think the deps are clear
Shachar Itzhaky (May 01 2021 at 13:56):Ah yes I was looking at the deps of 3.7.1 (which opam installed ;) ) which is why I did not see the ppxlib dep.
Shachar Itzhaky (May 01 2021 at 14:07):The weird thing is that elpi.1.11.2 is happy with ppxlib.0.15.0.
Emilio Jesús Gallego Arias (May 01 2021 at 14:12):Likely the < 0.15 constraint was added by some automatic tool
Emilio Jesús Gallego Arias (May 01 2021 at 14:12):it is common in opam world to add upper constraints when a new package break existing
Enrico Tassi (May 01 2021 at 14:13):Is the migration path hard? If not I can give a look and make a new elpi 1.13 release
Emilio Jesús Gallego Arias (May 01 2021 at 14:13):if it works you can always use --ignore-constrains-on
Emilio Jesús Gallego Arias (May 01 2021 at 14:13):@Enrico Tassi no idea, I think it depends on what you are using
Emilio Jesús Gallego Arias (May 01 2021 at 14:13):some APIs are the same, some not
Enrico Tassi (May 01 2021 at 14:13):I'd say nothing fancy...
Emilio Jesús Gallego Arias (May 01 2021 at 14:14):Yeah so maybe that is why old elpi works, maybe the new one is failing on something silly
Emilio Jesús Gallego Arias (May 01 2021 at 14:14):and the constraint was added after some CI failed
Emilio Jesús Gallego Arias (May 01 2021 at 14:14):yeah ppx 2.0 another pain-in-the-ass migration
Emilio Jesús Gallego Arias (May 01 2021 at 14:14)::joy: :joy: :joy: :joy: :joy: the joy of software development
Enrico Tassi (May 01 2021 at 14:16):the changelog for ppxlib does not seem huge
Enrico Tassi (May 01 2021 at 14:17):I'll give it a shot
Enrico Tassi (May 01 2021 at 14:17):actually, if you remove the dependency on ppxlib, elpi will compile
Enrico Tassi (May 01 2021 at 14:17):it has a local copy of the pre-processed files
Enrico Tassi (May 01 2021 at 14:18):dune will select the copy if ppx is not available
Enrico Tassi (May 01 2021 at 14:18):(that may be your quick fix)
Enrico Tassi (May 01 2021 at 14:18):I've never removed the dep from the opam package, mainly to get CI tell me when things break
Enrico Tassi (May 01 2021 at 14:19):maybe I should make it optional
Shachar Itzhaky (May 01 2021 at 14:21):Great!
Emilio Jesús Gallego Arias (May 01 2021 at 15:54):By the way I was writing an elpi overlay, installed 1.13.1 ignore the ppxlib constraint and things seem fine
Emilio Jesús Gallego Arias (May 01 2021 at 15:54):at least at compile time
Enrico Tassi (May 01 2021 at 17:45):I think I'll make a 1.13.2 using https://github.com/LPCIC/elpi/pull/100
Enrico Tassi (May 01 2021 at 17:46):and yes, the problem was in ppxfindcache which is only used for building
Enrico Tassi (May 01 2021 at 17:46):that PR removes it
Last updated: Jun 01 2023 at 12:01 UTC