I want to run a Qt 5 based application usind dynamic libraries on Linux. In summary, a script will copy the executable and other relevant files, including all required .so inside a lib folder, to the desired destination and a script calling gksudo will work as caller to the app.
Till now everything works fine till I call the executable script: the app doesn’t run. When I ask to run with sudo, it tells me that a library (Qt5SerialPort…) is missing. Running ldd over the actual executable I discover that the app is getting the required libs not from within the lib folder, but some apparent hard-coded paths.
I tried to solve this by using qt.conf but got no success. As note here, it would seem qt.conf isn’t actually supposed to work this way. Consulting the Qt documentation, I decided to use LD_LIBRARY_PATH to tell the linker where to find the libs since I was already using a script to run the app anyway. So the final, summarized script code is
#!/bin/sh LD_LIBRARY_PATH=lib/ export LD_LIBRARY_PATH sudo ldconfig #sometimes sudo /sbin/ldconfig -v gksudo "$INSPATH/myApp" #or sudo instead
Problem is that it is still not working. When I call echo $LD_LIBRARY_PATH, I can see the variable was properly edited, but when I call the run line (with sudo), it keeps telling me that lib wasn’t found.
What am I missing?
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Answer
sudo doesn’t pass LD_LIBRARY_PATH:
$ LD_LIBRARY_PATH=lib/ $ export LD_LIBRARY_PATH $ env | grep LD_LIBRARY_PATH LD_LIBRARY_PATH=lib/ $ sudo env | grep LD_LIBRARY_PATH
You can set it for the command run as root:
$ sudo env LD_LIBRARY_PATH=/lib env | grep LD_LIBRARY_PATH SUDO_COMMAND=/usr/bin/env LD_LIBRARY_PATH=/lib env LD_LIBRARY_PATH=/lib
You’ll want something like
sudo env LD_LIBRARY_PATH=/lib "$INSPATH/myApp"
As always, be careful with sudo!