Java Timezone setting does not work in ubuntu-latest any more

[thomasfox]

We have a groovy(JDK) project which runs tests which depend on the time zone. We use the set-timezone action to pin the time zone. Previously, ubuntu-latest was using Ubuntu 22.04 (see https://github.com/actions/runner-images/issues/10636) and it worked fine. Now, ubuntu-latest is using Ubuntu-24.04 and our builds fail because the java default time zone is set to Etc/UTC instead of Europe/Berlin as requested in the settings of set-timezone.

The set-timezone step within the Workflow is the first step in the workflow and is configured as follows:

    - uses: szenius/[email protected]
      with:
        timezoneLinux: "Europe/Berlin"
        timezoneMacos: "Europe/Berlin"
        timezoneWindows: "W. Europe Standard Time"

The test is:

import spock.lang.Specification

import java.time.ZoneId

class TimezoneSpecification extends Specification {
  def "Check Timezone"() {
    when:
    TimeZone timeZone = TimeZone.getDefault();

    then:
    timeZone.toZoneId() == ZoneId.of("Europe/Berlin")
  }
}

The test fails with:

Condition not satisfied:

timeZone.toZoneId() == ZoneId.of("Europe/Berlin")
|        |          |  |      |
|        Etc/UTC    |  |      Europe/Berlin
|                   |  class java.time.ZoneId
|                   false
sun.util.calendar.ZoneInfo[id="Etc/UTC",offset=0,dstSavings=0,useDaylight=false,transitions=0,lastRule=null]

	at TimezoneSpecification.Check Timezone(TimezoneSpecification.groovy:13)