Improve error diagnostics in UserCollector.

This CL makes the following changes to improve error diagnostics in
1. Add an error type to describe why the crash reporter fails to
   collects a user crash, which is reported to the crash server along
   with the "crash_reporter-user-collection" error signature.
2. Perform some preliminary validations of the core file before
   converting it to a minidump file using core2md.
3. Identify the case when a 32-bit core file is produced on a 64-bit
   platform as core2md currently cannot handle 32-bit core files on
   a 64-bit platform.

TEST=Tested the following:
1. emerge-{x86,amd64,arm}-generic crash-reporter
2. FEATURES="test" emerge-{x86,amd64,arm}-generic crash-reporter
3. Run the following autotest tests on x86-mario and stumpy64:
   - logging_CrashSender
   - logging_UserCrash

Change-Id: Ib50b4cc81a91f7cd75f9440005200d4027ce1f6f
Reviewed-by: Michael Krebs <>
Tested-by: Ben Chan <>
Commit-Ready: Ben Chan <>
3 files changed
tree: 2d895848309968660723d1954a5ac4948df2f67e
  1. crash_reporter/