mariadb-connector-c: fix socket path

[ajs124]

Motivation for this change

Fix socket path. The cmakeFlag changed from MYSQL_ to MARIADB_ some time recently.
This broke my setup.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

cc @thoughtpolice

[aanderse]

cc @Izorkin for informational purposes.

[dasJ]

@ajs124 Does this need a backport?

[ajs124]

No backport needed, I think. Maybe to 19.09? MariaDB packaging works quite different on 19.03.

[Izorkin]

No need change PR to staging?

[aanderse]

@GrahamcOfBorg test wordpress

@ajs124 I'm surprised this hasn't been merged yet... I assume without this change mariadb-connector-c throws a warning during compilation or something? Just so we can say we dotted our i's and crossed our t's can you please list an application or two you tested with this change?

[ajs124]

@aanderse That's the thing. No warning, no nothing. At least from what I saw. Just that the path is different in the library.

I tested it with my dovecot and @mmilata seems to have run into it with his sympa PR. I'm sure there are more things out there, but most applications probably connect to MariaDB over TCP, so they won't run into this.

[aanderse]

Turns out wordpress isn't a good test to show this works.

I assume this was mentioned in release notes at some point? Maybe we can link that? If @Izorkin approves this PR and @mmilata confirms this fixes his issue I would consider that adequate testing, review, and peer review for merge.

[ajs124]

I can't find a changelog entry, but this commit seems to be responsible. It's from 2016, but it seems like nixpkgs only has 3.x since August of this year.

[Izorkin]

I do not use a socket connection. I do not know how to check.

[Izorkin]

In source not found MYSQL_UNIX_ADDR.
Used only MARIADB_UNIX_ADDR
https://github.com/MariaDB/mariadb-connector-c/blob/c6403c4c847d94ed6b40d3fd128e729271867e75/CMakeLists.txt#L189-L191

[mmilata]

Confirming that this fixes my issue. Thanks for pinging me, yesterday I spent some time being really puzzled why it's happening without being able to trace it to this package.

[aanderse]

Seems straight forward enough. Merging based on feedback and detective work from all parties involved. Thanks everyone! 🎉