gradle2nix is very slow on rundeck

[lukegb]

I tried running it on e.g. https://github.com/rundeck/rundeck, and it took 1h 10m 51s to complete.

Is it expected to be this slow? I tried checking to see if I could increase the verbosity somehow but it looks like the only option is quiet, to reduce the verbosity, not to make it any shoutier.

It then appeared to miss some deps anyway:

* What went wrong:
A problem occurred evaluating project ':docker'.
> A problem occurred configuring project ':rundeckapp'.
   > Could not resolve all artifacts for configuration ':rundeckapp:classpath'.
      > Could not resolve io.spring.gradle:dependency-management-plugin:0.6.1.RELEASE.
        Required by:
            project :rundeckapp > org.grails:grails-gradle-plugin:4.0.3
         > No cached version of io.spring.gradle:dependency-management-plugin:0.6.1.RELEASE available for offline mode.
         > No cached version of io.spring.gradle:dependency-management-plugin:0.6.1.RELEASE available for offline mode.
      > Could not resolve javax.xml.bind:jaxb-api:2.3.0.
        Required by:
            project :rundeckapp > org.grails.plugins:database-migration:3.1.1.BUILD-SNAPSHOT:20201015.064425-2 > org.liquibase:liquibase-core:3.10.1
         > No cached version of javax.xml.bind:jaxb-api:2.3.0 available for offline mode.
         > No cached version of javax.xml.bind:jaxb-api:2.3.0 available for offline mode.
      > Could not resolve org.codehaus.plexus:plexus-classworlds:1.2-alpha-10.
        Required by:
            project :rundeckapp > org.grails:grails-gradle-plugin:4.0.3 > org.grails:grails-shell:4.0.3 > org.codehaus.plexus:plexus-component-api:1.0-alpha-33
         > No cached version of org.codehaus.plexus:plexus-classworlds:1.2-alpha-10 available for offline mode.
         > No cached version of org.codehaus.plexus:plexus-classworlds:1.2-alpha-10 available for offline mode.