Java properties are not set with `-Dkey=value`

[lolgab]

In Mill 1.0.0-RC1 if you do mill -Dmyprop=value the property is not set correctly.

//| mill-version: 1.0.0-RC1

println("ivy.home = " + sys.props.get("ivy.home"))

prints:

ivy.home = None

[lolgab]

The syntax is not normal Java syntax but like a Mill command line argument.
mill -D myprop=value or mill --define myprop=value works.

[lefou]

The syntax is not normal Java syntax but like a Mill command line argument. mill -D myprop=value or mill --define myprop=value works.

mill -Dprop=1 should also work in newer Mill versions.

• Since mainargs 0.6.0 - Allow short arguments and flags to be combined mainargs#102
• Used since Mill 0.11.7 - Bump MainArgs to 0.6.1 #2990

[lihaoyi]

@lolgab I put together an integration test, -Dprop=value seems to work correctly at least in the test #5212

[lihaoyi]

Going to close this if there's no further issues reported

[lefou]

I don't get it. We have a integration test that shows the working -Dprop=value processing, but it didn't work with Mill 1.0.0-RC1. So where was the issue?

[lefou]

So, this is still an issue in Mill 0.12.14

• Mill 0.12.14 Can't set Java system property with -Dprop=value but with -D prop=value #5416

[lefou]

@lolgab I put together an integration test, -Dprop=value seems to work correctly at least in the test #5212

Looks like this integration test is not tsting the -D/--define option of the Mill CLI but the .mill-jvm-opts file support.

[lihaoyi]

Seems like something to do with the graal native image. 1.0.0-RC3 has this bug, but 1.0.0-RC3-jvm does not. Most integration tests are run without the native image for performance, which is likely why the integration tests did not catch this

[lihaoyi]

Indeed, ./mill 'integration.feature[mill-jvm-property].local.daemon' and ./mill 'integration.feature[mill-jvm-property].packaged.daemon' pass but ./mill 'integration.feature[mill-jvm-property].native.daemon' fails