RFR: JDK-8297000 [jib] Add more friendly warning for proxy issues

Tue Nov 15 10:02:08 UTC 2022

When jib tries to download itself behind a proxy, sometimes it can get a different file than it expected. This can result in cryptic errors that are hard to troubleshoot. Let's handle this a little more gracefully by detecting it in the bootstrapper and printing an error.

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Commit messages:
 - JDK-8297000 [jib] Add more friendly warning for proxy issues

Changes: https://git.openjdk.org/jdk/pull/11159/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11159&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297000
  Stats: 13 lines in 1 file changed: 13 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/11159.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11159/head:pull/11159

PR: https://git.openjdk.org/jdk/pull/11159