Alexey recently improved the IOException text for child process errors with JDK-8325621. That is good, but can be expanded. It would be good to replace the "this is a list of all the things that may have failed" with a clear indication of what failed.

Note that this issue complements JDK-8357100, but has different users in mind.

JDK-8357100 is meant for knowledgeable developers, mostly us. The information will be fine-grained and will include non-error-information (e.g. it can be used to gain inside into the environment variables passed to child processes).

This issue has the end user in mind, with limited knowledge. It should be limited to error cases (spawn failed) and should report errors in a clear actionable way to the end user.