> As far as I understand these libraries are available, e.g. > > $ ldconfig -p | grep Qt5Network > libQt5Network.so.5 (libc6,x86-64) => > /lib/x86_64-linux-gnu/libQt5Network.so.5
I'm kind of surprised that is /lib and not /usr/lib (my Debian system has /usr/lib, I didn't know Ubuntu was different). In any case, do you also have
I think that's the file the linker expects to find, not the one with the version number. As I understand it, ldconfig is just telling you whether the run-time library exists, not whether the library needed for linking is present.
If that file is missing, why? It and the others should be provided by the qtbase5-dev (all except for Qt5Help) and qttools5-dev (Qt5Help) packages.
If it is present, then why is the linker not finding it? Also if it is present, what is the output of
ls -l /lib/x86_64-linux-gnu/libQt5Network.so
(or /usr/lib/... if that's where it is)?
The reason this is showing up as a problem with qscintilla and not Qt generally is that we check for qscintilla by linking a program. For the Qt libraries, we rely on the result of a pkg-config command. Maybe we should have configure double check by actually attempting to link a program instead of just trusting what pkg-config returns.
> but configure is not finding them > > $ grep cannot config.log > /usr/bin/ld: cannot find -lpthreads
The config.log file reports the results of all tests. Sometimes we check several different ways until we find something that works. So a "cannot find" message in the log doesn't necessarily mean that the feature is missing.