Hi,
I am using DEB_BUILD_OPTIONS options to have parallel jobs. Let me explain it more clear. I had a clean build at first. Then I did some changes in the packaging files such as .install etc.. Now if I could rebuild simply .deb files and do not clean the project's build directory that would save me more time. Because I haven't changed any configure or build options... just some small changes.
A typo in package name is another case where I don't want the rebuild the entire package. just try to make package from exists
I end up using dpkg-buildpackage -nc to skip the clean target.
For the record, I don't want this to be an option in the package. like never clean build directory. just for my test case like that. If I am changing stuff in debian/rules. I would prefer a clean build.
Here even with parallel on the system( a VM without much processing power), it took around 2hrs with the current settings. This largely depend on the system resources so that running parallel won't make much difference there.