Implement support for dynamic buildrequires in 'osc build'

[dmach]

Fixes: #1706

[codecov]

Codecov Report

❌ Patch coverage is 0% with 46 lines in your changes missing coverage. Please review.
✅ Project coverage is 33.80%. Comparing base (2ac8f0a) to head (14a0176).
⚠️ Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
osc/build.py	0.00%	46 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2151      +/-   ##
==========================================
- Coverage   33.86%   33.80%   -0.06%     
==========================================
  Files         199      199              
  Lines       27144    27190      +46     
==========================================
  Hits         9191     9191              
- Misses      17953    17999      +46     

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[darix]

woohoo +1

[dmach]

I got additional feedback and I should:

• check the exit codes; we should use only 11
• don't strip the versions in dependencies, use the deps as provided
• store the generated BRs on disk (similarly to buildconfig); properly handle --clean
• use /.build.packages/OTHER/_generated_buildreqs instead of parsing deps from nosrc.rpm
• when e.g. iteration 6 fails, don't start over, use previously stored deps; but make sure that re-using the buildroot to build another package in a project works fine

[mlschroe]

(I think build's exit code is 9, not 11)

[darix]

it checks for 9 and 11