Nested $^X launch fails after EnvDir -clean clears Java launcher environment #1465

Summary

The EnvDir distribution fails t/10_envdir_pl.t on PerlOnJava when envdir.pl runs a child $^X after loading EnvDir -clean.

Evidence

• Distribution: EnvDir-0.08
• Failing test: t/10_envdir_pl.t
• CPAN run: 20260921-102914-97159
• Source: CPAN random tester run 20260921-102914-97159
• PerlOnJava result: 25/26 tests passed; 1/7 test programs failed
• Standard Perl oracle: all 26 tests passed

The failing test expects:

FOO=foo
PATH=/env/bin

but the child produces no output and reports:

ERROR: PerlOnJava requires Java 24 or later; java was not found in PATH.

Reproduction

bin/envdir.pl uses:

use EnvDir 'envdir', -clean;

EnvDir -clean clears %ENV and sets PATH=/bin:/usr/bin; the test environment then overrides PATH with /env/bin. This removes the inherited PERLONJAVA_JAVA_BIN value. The child $^X is PerlOnJava's launcher shim, which then cannot locate Java and exits before running the requested child code.

The parent launcher works when PERLONJAVA_JAVA_BIN=/usr/bin/java is explicitly preserved, confirming that the failure is in launching a nested PerlOnJava process from a cleaned/restricted environment rather than in EnvDir's normal variable update behavior.

Expected behavior

A PerlOnJava program should be able to invoke $^X after deliberately modifying or cleaning %ENV, as standard Perl does. The nested launcher should retain or otherwise reliably locate the Java executable without requiring java to remain on the child process's modified PATH.

Suggested direction

Make the nested $^X launcher self-contained with respect to Java selection, or arrange for the selected Java path to survive launcher recursion without violating EnvDir -clean's requested child environment semantics. Add a regression test covering a nested $^X invocation after environment cleanup.