<div dir="ltr"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Ubuntu 17.04, which is based on Qt5.7.1, output from</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">`./output/bin/qgis`</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">`Couldn't load PyQt.</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Python support will be disabled. (a really big deal)</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Traceback (most recent call last):</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">   File "", line 1, in</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">ImportError: /usr/lib/x86_64-linux-gnu/libQt5Core.so.5: version `Qt_5.8'</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">not found (required by</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">/usr/local/lib/python3.5/dist-packages/PyQt5/QtCore.so)`</blockquote></blockquote><div><br></div><div>I have added a new page called 'Starting QGIS3 as seen from lddtree.sh'</div><div><br></div><div><a href="https://github.com/qgis/QGIS-Documentation/wiki/QGIS3-lddtree-sh">https://github.com/qgis/QGIS-Documentation/wiki/QGIS3-lddtree-sh</a> </div><div><br></div><div>As is often the case, complex Applications often fail for many different reasons.</div><div>This page show what steps where undertaken to resolve these problems.</div><div><br></div><div>lddtree.sh is a forked version of the original lddtree that, for me, brings better result. (source and download link are supplied on that page).<br></div><div><br></div><div>Here, in this case, it is important to check if both QGIS3 and PyQt5/QtCore.so use the same libQt5Core.so.5</div><div>- I believe it is save to assume that both MUST use the same QT5 Version, since QtCore.so is a (I believe) a function interface between python3 and libQt5Core</div><div><br></div><div>The page shows the result of both QGIS3 and PyQt5/QtCore.so (both of which work correctly) as an comparison.</div><div><br></div><div>In this case, I think, the cause of the problem is more likly to be that:</div><div>-> /usr/lib/x86_64-linux-gnu/libQt5Core.so.5</div><div>--> does not exsit on your system</div><div><br></div><div>Mark</div></div>