Merge ~sylvain-pineau/plainbox-provider-checkbox:fix-1903264 into plainbox-provider-checkbox:master

[Sylvain Pineau]

Fixes linked bug (missing dep on python3-serial)

[Sylvain Pineau (sylvain-pineau)]

self-approved

review: Approve

[Devices Certification Bot (ce-certification-qa)]

The merge was fine but running tests failed.

[xenial] [11:29:41] starting container
Device project added to xenial-testing
[focal] [11:29:55] starting container
[bionic] [11:29:56] starting container
Device project added to focal-testing
Device project added to bionic-testing
[xenial] [11:30:00] provisioning container
[bionic] [11:30:16] provisioning container
[focal] [11:30:16] provisioning container
[xenial] [11:30:19] Starting tests...
[xenial] Found a test script: ./requirements/container-tests-provider-checkbox
[bionic] [11:30:37] Starting tests...
[bionic] Found a test script: ./requirements/container-tests-provider-checkbox
[focal] [11:30:56] Starting tests...
[focal] Found a test script: ./requirements/container-tests-provider-checkbox
[xenial] [11:31:58] container-tests-provider-checkbox: PASS
[xenial] [11:31:58] Fixing file permissions in source directory
[xenial] [11:31:59] Destroying container
[bionic] [11:32:35] container-tests-provider-checkbox: PASS
[bionic] [11:32:35] Fixing file permissions in source directory
[bionic] [11:32:35] Destroying container
[focal] [11:32:47] container-tests-provider-checkbox: FAIL
[focal] output: https://paste.ubuntu.com/p/TMr9Z5QFSG/
[focal] [11:32:49] Fixing file permissions in source directory
[focal] [11:32:50] Destroying container

review: Needs Fixing

diff --git a/units/serial/packaging.pxu b/units/serial/packaging.pxu
new file mode 100644
index 0000000..da25e8e
--- /dev/null
+++ b/units/serial/packaging.pxu
@@ -0,0 +1,3 @@
+unit: packaging meta-data
+os-id: debian
+Depends: python3-serial