Hi there, it's my first bug report, sorry if it is not correct.
I just had some problems with mplex, not being able to create any files bigger than around 2 GB. After reading the docs of the package, I noticed that they talked about --enable-large-file, and all the ebuilds for this package I have on my tree pass a --enable-largefile (missing a minus sign on "largefile").
I have changed locally the ebuild of the version I wanted (~amd64, mjpegtools-1.9.0_rc3.ebuild), and now it is working.
Not sure about the other tools of this package... but at least mplex does seem to need the flag with the minus sign on "largefile", on the econf bit of the ebuild...
hope this helps, please let me know if you need more info from me.
stand by, I need to check something else