Turn the 'libunwind' build option into a boolean.

6 jobs for optional_libunwind in 17 minutes and 24 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
failed #220861
fedora

00:17:24

failed #220862
ubuntu

00:11:08

 
  Test
skipped #220863
deb-package
skipped #220864
flatpak
 
  Deploy
skipped #220865
review
skipped #220866
allowed to fail manual
stop_review
 
Name Stage Failure
failed
fedora Build

Ok: 1
Expected Fail: 0
Fail: 1
Unexpected Pass: 0
Skipped: 0
Timeout: 1

ERROR: Job failed: exit code 1
failed
ubuntu Build
1/2 engine-tests                            TIMEOUT 30.19 s 
2/2 client-tests OK 2.35 s

OK: 1
FAIL: 1
SKIP: 0
TIMEOUT: 1

ERROR: Job failed: exit code 1