Slic3r install fail

I have recently re-installed Linux Mint on my laptop and when I try to recompile Slic3r I get the following error:

src/admesh/stlinit.c: In function ‘void stl_read(stl_file*, int, int)’:
src/admesh/stlinit.c:292:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
fscanf(stl->fp, "endsolid\n");
^
src/admesh/stlinit.c:293:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
fscanf(stl->fp, "solid%*[^\n]\n"); // name might contain spaces so %*s doesn't work and it also can be empty (just "solid")
^
^Cerror building src/libslic3r/MotionPlanner.o from 'src/libslic3r/MotionPlanner.cpp' at /usr/share/perl/5.18/ExtUtils/CBuilder/Base.pm line 177.
The XS/C++ code failed to compile, aborting
peter@peter-Latitude-D630 ~ $

Any help greatly appreciated.

According to a reply to this post:

>The writer's of your libc have decided that the return value of scanf should not be ignored in most cases, so they have given it an attribute telling the compiler to give you a warning.

>If the return value is truly not needed, then you are fine. However, it is usually best to check it to make sure you actually successfully read what you think you did.

So it might be fine. I'm waiting to see if there are any problems since I got a simiar error but the process continued:

>src/admesh/stlinit.c: In function ‘void stl_read(stl_file*, int, int)’:
>src/admesh/stlinit.c:314:13: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
> fscanf(stl->fp, "endsolid\n");
> ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
>src/admesh/stlinit.c:315:13: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
> fscanf(stl->fp, "solid%*[^\n]\n"); // name might contain spaces so %*s doesn't work and it also can be empty (just "solid")

Also, I do realize I'm kind of necro-ing this thread, sorry about that. This post was one of the first that came up on google when searching about this error, and so I figured I might as well post what I'd found so far about it.

Sorry guys, I did fill in the txt but tried editing the subject and the txt disappeared ..
Using an Imac and tried updating Slic3r but got the message " Failed to change owner & group for wx-config with owner ID 501 and group ID 80. "
Any ideas anybody? Fortunately it drops back to the old install but I can take it no further. Thanks guys..

You need root access to change owners...

so try sudo

But why would I want to change owners??? I may as well delete the s/ware and reinstall?? Or am I missing something.... ?
Thanks again.