mongoc-sys semver specification

[kamulos]

I am using a patched mongoc-sys which I also depend on at a different point in my program, so this might be a less common issue, but I think it is really easy to fix, so here it is:

• I think the specification 1.17.5-1 is a prerelease specification
• In my (hacky) system this leads to a case where I only get updated to the mongo_driver version that depends on 1.17.5 if I specify the dependency 1.17. To upgrade to the mongo_driver depending on 1.17.5-1 I have to set this exact version in the other locations
• A really simple fix might be to use 1.17.5+1

Source: https://semver.org/#spec-item-10