most basic way would be get a full git clone and compile it from per commit it changed: but it looks like a large bundle for compile a single package.
Bisect picks commits for you to narrow down the window. You provide the working commit and the one where you're sure it broke. You can also tell git to skip commits if recall correctly. So it should be easy to filter out all commits not relevant to the package you're bisecting.
You could checkout the specific tag or version and compile only the package?
If I need to compare versions I build the image builder with all packages so I have then to only recompile the single specific package.
Don't know if that's the best solution to that issue...
Do you mean bisecting upstream changes in a package? When upstream version 1.1.0 worked ok, but 1.1.2 does not?
If OpenWrt Makefile jumped over some upstream minor versions, you might try modifying the Makefile to compile those minor versions and try to narrow the upstream range.
Then you could look at the upstream change log / commit log, and try to figure out suspect commits there. It could be possible to revert those (hopefully simple) changes with a local patches in OpenWrt.
If there are lots of commits and you really need to bisect upstream commits between their release point, then you may need to change OpenWrt Makefile to download upstream git commit hash based versions, and compile those, manually bisecting.