Package ppx_deriving_decoders.0.1

[benbellick]

ppx_deriving_decoders.0.1

Deriving Decoders using PPX
Using mattjbray/ocaml-decoders, use a ppx to automatically generate instances of a decoder for a particular type using PPX.

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• Homepage: https://github.com/benbellick/ppx_deriving_decoders
• Source repo: git+https://github.com/benbellick/ppx_deriving_decoders.git
• Bug tracker: https://github.com/benbellick/ppx_deriving_decoders/issues

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🐫 Pull-request generated by opam-publish v2.4.0

[shonfeder]

Hello 👋 Thank you for publishing your package!

Since it looks like this is your first time publishing a package to opam, allow me offer a warm welcome and a bit of an intro :)

We run a CI system to ensure that packages can be installed on all intended systems. You can see the results for your PR at https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/88cc1e996b0437ff2d34fd37af31645a80408a79 (or by clicking the Details link next to the opam-ci status check).

This shows the results of the builds and tests across our build matrix. Because we build and test on such a large matrix, it is very common for errors to be identified during package publication.

In my following comments and suggestions, I'll try to provide pointers and suggestions to get everything squared away. Please let us know if you have any questions, as we are here to help :)

[shonfeder]

Aside from the lower bound error noted below, I see we are also seeing a failure to build decoders on arm32 (https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/88cc1e996b0437ff2d34fd37af31645a80408a79/variant/extras,arm32-ocaml-5.2,ppx_deriving_decoders.0.1) and x86_32 . In both cases it looks like the following:

#=== ERROR while compiling decoders.1.0.0 =====================================#
# context              2.4.0~alpha1~dev | linux/arm32 | ocaml-base-compiler.5.2.0 | file:///home/opam/opam-repository
# path                 ~/.opam/5.2/.opam-switch/build/decoders.1.0.0
# command              ~/.opam/opam-init/hooks/sandbox.sh build dune build -p decoders -j 15 @install
# exit-code            1
# env-file             ~/.opam/log/decoders-7-b537cc.env
# output-file          ~/.opam/log/decoders-7-b537cc.out
### output ###
# File "src/dune", lines 6-11, characters 0-105:
#  6 | (rule
#  7 |  (targets shims_let_ops_.ml)
#  8 |  (action
#  9 |   (with-stdout-to
# 10 |    %{targets}
# 11 |    (run ./gen/mkshims.exe))))
# Error: No rule found for src/gen/mkshims.exe

This is a problem with the docoder dependency rather than this package. I've reported it upstream in mattjbray/ocaml-decoders#75

[shonfeder]

We are seeing a syntax error on https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/88cc1e996b0437ff2d34fd37af31645a80408a79/variant/compilers,4.08,ppx_deriving_decoders.0.1,lower-bounds

-> installed ppxlib.0.7.0
[ERROR] The compilation of ppx_deriving_decoders.0.1 failed at "dune build -p ppx_deriving_decoders -j 39 @install".

#=== ERROR while compiling ppx_deriving_decoders.0.1 ==========================#
# context              2.4.0~alpha1~dev | linux/x86_64 | ocaml-base-compiler.4.08.1 | pinned(https://github.com/benbellick/ppx_deriving_decoders/archive/refs/tags/0.1.tar.gz)
# path                 ~/.opam/4.08/.opam-switch/build/ppx_deriving_decoders.0.1
# command              ~/.opam/opam-init/hooks/sandbox.sh build dune build -p ppx_deriving_decoders -j 39 @install
# exit-code            1
# env-file             ~/.opam/log/ppx_deriving_decoders-7-6cd26d.env
# output-file          ~/.opam/log/ppx_deriving_decoders-7-6cd26d.out
### output ###
# (cd _build/.sandbox/3b8b8817e830e46625b42d49541b2972/default && .ppx/0224ad3443a846e54f1637fccb074e7d/ppx.exe --cookie 'library-name="ppx_deriving_decoders"' -o src/expander.pp.ml --impl src/expander.ml -corrected-suffix .ppx-corrected -diff-cmd - -dump-ast)
# File "src/expander.ml", line 251, characters 13-14:
# 251 |           let* [%p var_pat] = field [%e str] [%e subexpr] in
#                    ^
# Error: Syntax error

The error is pointing to https://github.com/benbellick/ppx_deriving_decoders/blob/bed675eaf4a0fa73cf8a2fd5eab27343bd3a596a/src/expander.ml#L251 and teh test is a lower bounds test, wherein we check that packages can build with the lower bounds of the dependencies they declare.

Since ocaml 4.08 supported let-binding operators already, I'm wondering if we may need to increase the lower bound on ppxlib here to, e.g.,

Suggested change

	"ppxlib"
	"ppxlib" {>= "0.20.0"}

[benbellick]

Ah addressing this one, but amazing! Thanks for the help 😄

[shonfeder]

Great! The lower bounds checks are passing and only the decoder issue persists, and we’ll tackle that up stream. Thanks very much for authoring and sharing this useful package :)

Consider announcing it on discuss.ocaml.org :)