gitlab-ci: avoid collisions with other projects' sccache servers

Shell runners might be running multiple projects in parallel. Avoid
conflicting with their sccache servers by using different port
selections.
14 jobs for !765 with ci-config-sync in 11 minutes and 53 seconds (queued for 6 seconds)
detached
Status Job ID Name Coverage
  Build
passed #5299984
cmb linux docker build
build:fedora31-asan

00:00:24

passed #5299987
cmb linux docker build
build:fedora31-coverage

00:00:20

passed #5299983
cmb linux docker build
build:fedora31-plain

00:00:25

passed #5299986
cmb linux docker build
build:fedora31-tidy

00:01:03

passed #5299985
cmb linux docker build
build:fedora31-ubsan

00:00:24

passed #5299988
cmb macos shell xcode-11.5 nonconcurrent
build:macos-plain

00:02:16

passed #5299989
cmb windows shell vs2019 msvc-19.26 nonconcurrent
build:windows-vs2019-ninja

00:02:48

 
  Test
failed #5299991
cmb linux docker x11 privileged
test:fedora31-asan

00:00:29

failed #5299993
cmb linux docker x11
test:fedora31-coverage

00:00:32

failed #5299990
cmb linux docker x11
test:fedora31-plain

00:00:47

failed #5299992
cmb linux docker x11 privileged
test:fedora31-ubsan

00:01:06

failed #5299994
cmb macos shell xcode-11.5 nonconcurrent
test:macos-plain

00:03:27

failed #5299995
cmb windows shell vs2019 msvc-19.26 nonconcurrent
test:windows-vs2019-ninja

00:02:47

 
  Analyze
skipped #5299996
cmb linux docker build
analyze:fedora31-coverage
 
Name Stage Failure
failed
test:windows-vs2019-ninja Test
   Send to group: merge-requests
SubmitURL: https://open.cdash.org/submit.php?project=CMB
Uploaded: C:/glr/builds/cmb/cmb-ci/build/Testing/20201027-1439/Test.xml
Submission successful
CMake Error at C:/glr/builds/cmb/cmb-ci/.gitlab/ci/ctest_test.cmake:22 (message):
Failed to test


ERROR: Job failed: exit status 1
failed
test:macos-plain Test
   Send to group: merge-requests
SubmitURL: https://open.cdash.org/submit.php?project=CMB
Uploaded: /opt/glr/cmb/cmb-ci/build/Testing/20201027-1429/Test.xml
Submission successful
CMake Error at /opt/glr/cmb/cmb-ci/.gitlab/ci/ctest_test.cmake:22 (message):
Failed to test


ERROR: Job failed: exit status 1
failed
test:fedora31-ubsan Test
   Uploaded: /builds/gitlab-kitware-sciviz-ci/build/Testing/20201027-1427/DynamicAnalysis.xml
Submission successful
CMake Error at /builds/gitlab-kitware-sciviz-ci/.gitlab/ci/ctest_memcheck.cmake:26 (message):
Failed to test


Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
test:fedora31-asan Test
   Uploaded: /builds/gitlab-kitware-sciviz-ci/build/Testing/20201027-1427/DynamicAnalysis.xml
Submission successful
CMake Error at /builds/gitlab-kitware-sciviz-ci/.gitlab/ci/ctest_memcheck.cmake:26 (message):
Failed to test


Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
test:fedora31-plain Test
   Uploaded: /builds/gitlab-kitware-sciviz-ci/build/Testing/20201027-1427/Test.xml
Submission successful
CMake Error at /builds/gitlab-kitware-sciviz-ci/.gitlab/ci/ctest_test.cmake:22 (message):
Failed to test


Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
test:fedora31-coverage Test
   Uploaded: /builds/gitlab-kitware-sciviz-ci/build/Testing/20201027-1428/Test.xml
Submission successful
CMake Error at /builds/gitlab-kitware-sciviz-ci/.gitlab/ci/ctest_test.cmake:22 (message):
Failed to test


Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1