Originally Posted by Ahmad Samir
Sigil bundles some libraries in its source repository, e.g. Boost, zlib, MiniZip, hunspell, PCRE.... etc; FORCE_BUNDLED_COPIES makes Sigil use those bundled libraries instead of using the system-provided libraries (if they're installed on your system).
For example if you have pcre-devel installed and build with -DFORCE_BUNDLED_COPIES=1, then Sigil will use the bundled pcre not the system-provided ones.
Thanks, Ahmad. At the moment, I don't have any of those installed, so that's how I was able to get away without it so far.