...slimserver-8.3.1/CPAN/XML/Parser.pm line 20

In reply to @adam:robins.wtf
Ok, so I’ll remove any that we’re providing and see where that takes me 

Managed to get slimserver.pl not fail at compiling by providing the following buildInputs

  buildInputs = with perlPackages; [ DBI EV ClassXSAccessor DBDSQLite CarpClan FileSlurp ExporterLite XMLParser HTMLParser JSONXS DigestSHA1 YAMLLibYAML SubName CryptOpenSSLRSA IOSocketSSL
                                     AnyEvent ClassDataInheritable ClassInspector DBIxClass DataURIEncode FileBOM FileNext
                                     FileWhich IOString TieCacheLRUExpires ImageScale JSONXS JSONXSVersionOneAndTwo LogLog4perl PathClass ProcBackground SQLAbstract TextUnidecode
                                     TieCacheLRU TieRegexpHash XMLSimple URIFind HTTPDaemon DataDump
                                   ];

And removed the CPAN directory in prePatch with rm -r CPAN

In reply to @adam:robins.wtf
Ok, so I’ll remove any that we’re providing and see where that takes me 

Managed to get slimserver.pl not fail at compiling by providing the following buildInputs

  buildInputs = with perlPackages; [ DBI EV ClassXSAccessor DBDSQLite CarpClan FileSlurp ExporterLite XMLParser HTMLParser JSONXS DigestSHA1 YAMLLibYAML SubName CryptOpenSSLRSA IOSocketSSL
                                     AnyEvent ClassDataInheritable ClassInspector DBIxClass DataURIEncode FileBOM FileNext
                                     FileWhich IOString TieCacheLRUExpires ImageScale JSONXS JSONXSVersionOneAndTwo LogLog4perl PathClass ProcBackground SQLAbstract TextUnidecode
                                     TieCacheLRU TieRegexpHash XMLSimple URIFind HTTPDaemon DataDump
                                   ];

And removed the CPAN directory in prePatch with rm -r CPAN

kept just the upstream vendored DBIx, fixed some more missing modules, and then hit this

machine # [    7.429205] slimserver.pl[851]: [23-11-06 18:25:35.4817] Carp::Clan::__ANON__ (221) Warning: Carp::Clan::__ANON__(): DBI Exception: DBD::SQLite::db prepare_cached failed: no such function: ARRAY [for Statement "SELECT me.id, me.name, me.namesort, me.musicmagic_mixable, me.namesearch, me.musicbrainz_id, me.extid FROM contributors me WHERE ARRAY(0x26996f0) = ?"] at /nix/store/5k8n8yid998qjxlhmzysmrpgd6s45r1g-perl5.36.1-slimserver-8.3.1/Slim/Schema/Storage.pm line 125

In reply to @adam:robins.wtf
made some progress, just trying to iterate to find the exact set of modules we have to keep from upstream

In reply to @stigo:matrix.org
I'll have a closer look at your PR soon