ghc-cabal: Use fromFlagOrDefault instead of fromFlag

As fromFlag is partial. The only case where we used fromFlag is when
determining whether to strip libraries; we now assume that we shouldn't.
22 jobs for !1446 with wip/fix-ghc-cabal in 489 minutes and 35 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Lint
passed #127458
lint
ghc-linters

00:00:20

passed #127459
lint
lint-linters

00:00:21

passed #127462
lint
lint-submods-mr

00:00:30

passed #127460
lint
lint-testsuite

00:00:24

passed #127461
lint
typecheck-testsuite

00:00:24

 
  Build
passed #127464
x86_64-linux
hadrian-ghc-in-ghci

00:19:27

passed #127466
x86_64-linux
release-x86_64-linux-deb9-dwarf

01:11:47

passed #127465
x86_64-linux
validate-x86_64-linux-deb9-debug

03:00:23

passed #127463
x86_64-linux
validate-x86_64-linux-deb9-hadrian

03:04:53

 
  Full Build
failed #127468
aarch64-linux allowed to fail
validate-aarch64-linux-deb9

03:27:10

passed #127469
x86_64-linux
validate-i386-linux-deb9

01:46:57

passed #127939
x86_64-darwin
validate-x86_64-darwin

00:56:27

passed #127470
x86_64-linux
validate-x86_64-linux-deb9-integer-simple

01:46:23

passed #127471
x86_64-linux
validate-x86_64-linux-deb9-unreg

02:12:48

passed #127472
x86_64-linux
validate-x86_64-linux-fedora27

01:16:12

failed #127474
x86_64-windows allowed to fail
validate-x86_64-windows

02:32:50

passed #127473
x86_64-windows
validate-x86_64-windows-hadrian

01:19:22

failed #127467
x86_64-darwin
validate-x86_64-darwin

00:57:47

 
  Cleanup
passed #127475
x86_64-darwin
cleanup-darwin

00:00:08

 
  Packaging
passed #127476
x86_64-linux
doc-tarball

00:04:57

 
  Testing
manual #127477
x86_64-linux allowed to fail manual
hackage
passed #127478
x86_64-linux
perf-nofib

00:20:31

 
Name Stage Failure
failed
validate-aarch64-linux-deb9 Full Build
$ cp -Rf $HOME/.cabal cabal-cache
Uploading artifacts...
ghc-*.tar.xz: found 1 matching files
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=127468 responseStatus=201 Created token=FAr5XdTn
Uploading artifacts...
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=127468 responseStatus=201 Created token=FAr5XdTn
ERROR: Job failed: exit code 1
failed
validate-x86_64-windows Full Build
junit.xml: found 1 matching files                  
WARNING: Failed to load system CertPool:crypto/x509: system root pool is not available on Windows
Uploading artifacts to coordinator... ok
id=127474 responseStatus=201 Created token=D7ui7gKi
Uploading artifacts...
Runtime platform
arch=amd64 os=windows pid=5572 revision=1f513601 version=11.10.1
junit.xml: found 1 matching files

WARNING: Failed to load system CertPool:crypto/x509: system root pool is not available on Windows
Uploading artifacts to coordinator... ok
id=127474 responseStatus=201 Created token=D7ui7gKi
ERROR: Job failed: exit status 2