Add graphics package to existing switches

[dra27]

At present, the graphics package allows the absence of the OCaml graphics library to be detected as a dependency failure (which is neater than a build system error). This PR enhances that by building and installing the graphics library if it's missing. Here's an example:

dra@bionic:~$ ocamlfind query graphics
ocamlfind: Package `graphics' not found

dra@bionic:~$ opam install graphics
The following actions will be performed:
  ∗ install graphics 1.0

<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[ERROR] The compilation of graphics failed at "/home/dra/.opam/opam-init/hooks/sandbox.sh build ocamlc -custom graphics.cma -o test".

#=== ERROR while compiling graphics.1.0 =======================================#
...
<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
┌─ The following actions failed
│ λ build graphics 1.0
└─ 
╶─ No changes have been performed

<><> graphics.1.0 troubleshooting <><><><><><><><><><><><><><><><><><><><><><><>
=> This package checks whether the Graphics library was compiled.

dra@bionic:~$ opam remote add graphics git+https://github.com/dra27/opam-repository.git#graphics
...

dra@bionic:~$ opam install graphics --yes
The following actions will be performed:
  ∗ install conf-pkg-config 1.1    [required by conf-libX11]
  ∗ install conf-libX11     1      [required by graphics]
  ∗ install graphics        4.06.1
===== ∗ 3 =====

<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[graphics.4.06.1] found in cache

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
∗ installed conf-pkg-config.1.1
∗ installed conf-libX11.1
∗ installed graphics.4.06.1
Done.

dra@bionic:~$ ocamlfind query graphics
/home/dra/.opam/ocaml-with-graphics/lib/graphics

For system switches, the library is installed as a findlib package only so, just as with nums in 4.06.0 onwards, users of system switches will need to be using something more sophisticated than #load "graphics.cma". For opam-built compilers, they are installed to the OCaml libdir as OCaml would - the package installs a META file if ocamlfind has already been installed (ocamlfind will automatically generate META on any future installations).

A conf-libX11 package is added which at the moment is based entirely on pkg-config. Part of removing graph and win32graph from OCaml may include transferring the configure logic to this package, but for now I kept it simple.

Reviewers may wish to note that the install.sh is identical in all packages and the opam file differs only by version-specific patches. Originally I did this all in opam files, but it's really difficult to deal with both system and non-system compilers and the fact that graphics may be already installed in the commands, so a script seemed somewhat less unclear.

These packages were generated by the scripts in dra27@14f9326.

[camelus]

☀️ All lint checks passed 0c4c0de

• These packages passed lint tests: conf-libX11.1, graphics.3.07+1, graphics.3.07+2, graphics.3.07, graphics.3.08.0, graphics.3.08.1, graphics.3.08.2, graphics.3.08.3, graphics.3.08.4, graphics.3.09.0, graphics.3.09.1, graphics.3.09.2, graphics.3.09.3, graphics.3.10.0, graphics.3.10.1, graphics.3.10.2, graphics.3.11.0, graphics.3.11.1, graphics.3.11.2, graphics.3.12.0, graphics.3.12.1, graphics.4.00.0, graphics.4.00.1, graphics.4.01.0, graphics.4.02.0, graphics.4.02.1, graphics.4.02.2, graphics.4.02.3, graphics.4.03.0, graphics.4.04.0, graphics.4.04.1, graphics.4.04.2, graphics.4.05.0, graphics.4.06.0, graphics.4.06.1, graphics.4.07.0, graphics.4.07.1

---

☀️ Installability check (10785 → 10822)

• new installable packages (37): conf-libX11.1 graphics.3.07 graphics.3.07+1 graphics.3.07+2 graphics.3.08.0 graphics.3.08.1 graphics.3.08.2 graphics.3.08.3 graphics.3.08.4 graphics.3.09.0 graphics.3.09.1 graphics.3.09.2 graphics.3.09.3 graphics.3.10.0 graphics.3.10.1 graphics.3.10.2 graphics.3.11.0 graphics.3.11.1 graphics.3.11.2 graphics.3.12.0 graphics.3.12.1 graphics.4.00.0 graphics.4.00.1 graphics.4.01.0 graphics.4.02.0 graphics.4.02.1 graphics.4.02.2 graphics.4.02.3 graphics.4.03.0 graphics.4.04.0 graphics.4.04.1 graphics.4.04.2 graphics.4.05.0 graphics.4.06.0 graphics.4.06.1 graphics.4.07.0 graphics.4.07.1

[dra27]

The Camelus broken package is because this PR assumes #12669.

#12451 fixed the checksum for the clang patch in 4.00.1, but for some reason skipped 4.01.0, so that's bundled in here.

I've added stuff which seems to fix pkg-config detection of X11 on macOS!

I'm at a loss as to how to make DataKitCI happy - the first time it installed conf-pkg-config and conf-libX11 and complained at ./install.sh in the graphics package. So I changed it to be sh ./install.sh but then DataKitCI the second time suddenly can't install conf-pkg-config. Meh.

[kit-ty-kate]

#=== ERROR while compiling graphics.4.07.0 ====================================#
"./install.sh": command not found.

I guess there is a chmod +x missing in this file

[kit-ty-kate]

I don't understand the problem.. :/ The file already has the right permissions.. Anyone has any idea?

[dra27]

I tried a test commit changing the call to be sh ./install.sh but then I got errors about being unable to install conf-pkg-config instead :-/

[dra27]

Basically, there are various things which could be going on (error in opam’s logic to find the command, error in the script, etc.), but I gave up when it appeared that the process wasn’t stable.

[dra27]

@samoht - any ideas? avsm I know is way too snowed under to be able to look at this atm (of course, you may be too!)

[dra27]

I think I may have solved this - please don't merge, even if CI passes this time round

[kit-ty-kate]

Ahhh

[WARNING] Could not read file /home/opam/.opam/repo/default/packages/graphics/graphics.4.07.1/opam. skipping:
          At /home/opam/.opam/repo/default/packages/graphics/graphics.4.07.1/opam:30:2:
          Parse error

Somehow it's a silent error :/

[kit-ty-kate]

I've pushed a fix to get the error sooner next time: avsm/mirage-ci@5d761ef

[dra27]

Thanks, @kit-ty-kate! The log now reveals the problem as well:

Processing  5/6: [graphics: ls install.sh]
+ /bin/ls "-l" "install.sh" (CWD=/home/opam/.opam/4.07/.opam-switch/build/graphics.4.07.1)
- -rw-r--r-- 1 opam opam 1980 Nov  1 18:57 install.sh
Processing  5/6: [graphics: ocaml unix.cma]
+ /home/opam/.opam/4.07/bin/ocaml "unix.cma" "probe.ml" (CWD=/home/opam/.opam/4.07/.opam-switch/build/graphics.4.07.1)
- uid=1000  groups=  stat=1000,1000,644

#=== ERROR while compiling graphics.4.07.1 ====================================#
"./install.sh": command not found.

The error message from opam should be better (ocaml/opam#3649), but why is the file system not correct for DataKit CI?

[dra27]

OK, not sure how much more poking around I can sensibly do: https://ci.ocamllabs.io/log/saved/docker-build-2b6c0b6fad0045aab224e73d3691e9d1/e4aa5092ef8815c8d2ddad5b249ea940689f19ce shows that the install.sh files are definitely checked out from git with mode 755 but by the time they're ending up in the build directory they've lost them. Is one of the intermediate container snapshots not preserving execute bits for some reason?

[kit-ty-kate]

This looks ok. Should I go ahead and merge it?

[dra27]

Huzzah - finally green! Please do 🙂

[kit-ty-kate]

Thanks a lot!!