The `gprof' build type compiles and links with -pg option with gcc.
- o --with-extra-lib=DIRECTORY that specifies the path where LyX will
- find extra libraries (qt4) it needs. Defaults to NONE
+o --disable-qt5 that forces configuration with Qt 4.x when Qt 5.x is
+ also available. By default Qt5 is tried first, and then Qt4.
+
+o --with-extra-lib=DIRECTORY that specifies the path where LyX will
+ find extra libraries (like Qt) it needs. Defaults to NONE
(i.e. search in standard places). You can specify several
directories, separated by colons.