[gpg]
    format = ssh
[gpg "ssh"]
    program = /Applications/1Password.app/Contents/MacOS/op-ssh-sign
[commit]
    gpgsign = true 

Exception in thread "main" java.lang.IllegalArgumentException: Invalid value: gpg.format=ssh
        at org.eclipse.jgit.lib.DefaultTypedConfigGetter.getEnum(DefaultTypedConfigGetter.java:105)
        at org.eclipse.jgit.lib.Config.getEnum(Config.java:403)
        at org.eclipse.jgit.lib.GpgConfig.<init>(GpgConfig.java:86)
        at org.eclipse.jgit.api.CommitCommand.processOptions(CommitCommand.java:620)
        at org.eclipse.jgit.api.CommitCommand.call(CommitCommand.java:180)
        at org.spigotmc.builder.Builder.main(Builder.java:677)
        at org.spigotmc.builder.Bootstrap.main(Bootstrap.java:27)