Reproduce bug: `dynverAssertTagVersion` is `null` in onLoad

[mkurz]

Let's see if CI complains here, details follow.

[mkurz]

@eed3si9n @dwijnand @ckipp01 @SethTisue the 5.0.0 release is broken. Adding

Global / onLoad := (Global / onLoad).value.andThen { s =>
  dynverAssertTagVersion.value
  s
}

like suggested in the readme prevents sbt from starting. Seems like dynverAssertTagVersion is null.

Funny thing is there is a scripted test, that checks that code: https://github.com/sbt/sbt-dynver/blob/main/sbtdynver/src/sbt-test/dynver/assert-tag-version/build.sbt However that test is expected to fail: https://github.com/sbt/sbt-dynver/blob/main/sbtdynver/src/sbt-test/dynver/assert-tag-version/test#LL1C1-L1C1 so that's why no one noticed so far.

Can you take a look what's going on here? Seems to be some variable initialization problem (?) (I am quite busy myself....)

Side note: To be able to run the scripted tests on my machine I had to set the sbt version to 1.2.0 here: https://github.com/sbt/sbt-dynver/blob/335a19826b111db0490556c635a2c85faacedf7e/build.sbt#L59-L63 1.1.0 gave me errors like

[info] [error] java.nio.file.NoSuchFileException: /tmp/sbt_bad2f8c9/custom-version-string/project/target/scala-2.12/sbt-1.0/classes

[eed3si9n]

Here's my PR for this - https://github.com/sbt/sbt-dynver/pull/255

[mkurz]

@eed3si9n Thanks, PR LGTM!