Re: Curious link error: symbols not found

[Thomas Danckaert <post@thomasdanckaert.be>]

From: Hartmut Goebel <h.goebel@crazy-compilers.com>
Subject: Curious link error: symbols not found
Date: Thu, 23 Mar 2017 15:33:46 +0100

> Hi,
>
> just today I tried to compile "ktouch", a KDE and QT application. 
> This
> failed with *link* errors (see below), which I find very curious.
>
> Let's look at the first error message: To my understanding.the 
> package
> "kcmutils" should reference to *exactly* the version of Qt (or what
> ever), it was build for. So how can it be that some symbol is not 
> found?
>
> I tried force-re-building qtbase and the effected packed (as listed
> below), but this did not solve the issue.
>
> /gnu/store/…-kcmutils-5.28.0/lib/libKF5KCMUtils.so.5.28.0:
> undefined reference to `qt_version_tag@Qt_5.7'
> [...]

Perhaps the monolithic Qt (which is at 5.6x) as well as the modular 
Qt are in your profile? If the so from the monolithic Qt is found by 
the linker (or already at profile creation time, as I think the 2 Qt 
versions would lead to collisions), maybe such errors could occur?

Thomas