Cannot build project with GDC 12

[SingingBush]

With gdc 12

$ gdc-12 --version
gdc-12 (Ubuntu 12.3.0-1ubuntu1~22.04) 12.3.0

Running dub test --coverage --compiler=gdc-12 fails as etc.c.sqlite3 cannot be imported

$ dub test --coverage --compiler=gdc-12
    Fetching d-unit 0.10.2 (getting selected version)
    Fetching odbc 1.0.0 (getting selected version)
    Fetching derelict-pq 2.2.0 (getting selected version)
    Fetching undead 1.1.[8](https://github.com/buggins/ddbc/actions/runs/7193831941/job/19593087831#step:6:9) (getting selected version)
    Fetching derelict-util 2.0.6 (getting selected version)
    Fetching mysql-native 3.1.0 (getting selected version)
             Generating test runner configuration 'ddbc-test-full' for 'full' (staticLibrary).
    Starting Performing "unittest-cov" build using gdc-[12](https://github.com/buggins/ddbc/actions/runs/7193831941/job/19593087831#step:6:13) for x86_64.
    Building derelict-util 2.0.6: building configuration [library]
    Building derelict-pq 2.2.0: building configuration [library]
    Building mysql-native 3.1.0: building configuration [library]
    Building odbc 1.0.0: building configuration [library]
    Building ddbc ~ci/gdc_builds: building configuration [ddbc-test-full]
source/ddbc/drivers/sqliteddbc.d:48:12: error: unable to read module ‘sqlite3’
   48 |     import etc.c.sqlite3;
      |            ^
source/ddbc/drivers/sqliteddbc.d:48:12: note: Expected 'etc/c/sqlite3.d' or 'etc/c/sqlite3/package.d' in one of the following import paths:
   48 |     import etc.c.sqlite3;
      |            ^
import path[0] = /usr/lib/gcc/x86_64-linux-gnu/12/include/d
import path[1] = /home/runner/work/ddbc/ddbc/source
import path[2] = /home/runner/.dub/cache/ddbc/~ci/gdc_builds/code/ddbc-test-full-unittest-cov-SepMcQQP0ppXiSBNVyHZMg
import path[3] = /home/runner/.dub/packages/derelict-pq/2.2.0/derelict-pq/source
import path[4] = /home/runner/.dub/packages/derelict-util/2.0.6/derelict-util/source
import path[5] = /home/runner/.dub/packages/mysql-native/3.1.0/mysql-native/source
import path[6] = /home/runner/.dub/packages/odbc/1.0.0/odbc/source
Error gdc-12 failed with exit code 1.
Error: Process completed with exit code 2.

[SingingBush]

Nothing has changed in GCC, 14.2.0 still lacks etc/c/sqlite3.d. It's likely that this will always be the case so any code that relies on sqlite will have to be modified. The imports could be wrapped in static if:

static if(__traits(compiles, (){ import etc.c.sqlite3; } )) {
    import etc.c.sqlite3;
} else {
    // We need this due to GDC not having etc.c.sqlite3
    pragma(lib, "sqlite3");
}

then attempt to compile using both dmd and gdc and work through any compile errors in a similar way.

Failing that another alternative could be to have GDC specific code by having something like "sourceFiles-unix-gdc": ["source/ddbc/drivers/sqliteddbc-gdc.d"] and "excludedSourceFiles-unix-gdc": ["source/ddbc/drivers/sqliteddbc.d"] in the dub.json file. There would still be a need to sort all the tests that assume sqlite is available though.