Two errors thrown for one root cause re licenses
The new SPDX related license errors work properly, but we have a somewhat unnecessary double error for a single root cause.
namcap E: GPL is not a valid SPDX license identifier. See https://spdx.org/licenses/ for valid identifiers, or prefix the identifier with 'LicenseRef-', if it is custom.
namcap E: Uncommon license identifiers such as 'GPL' require license files below /usr/share/licenses/namcap/. Found 0/1
The second warning here is regarding something that we can't properly parse as long as the first one isn't fixed. This might lead people astray if they try to fix errors from the bottom up or all at once instead of one at a time top down. In the latter case the second error will disappear when fixing the first error, but that's kind of confusing. We should probably just skip the second lint if the first one didn't pass.