Re: [bug-gnuastro] Bug report with make check during installation

[Mohammad Akhlaghi]

Dear Lars,

Thank you very much for the report and also sending the corresponding 
`test-suite.log' file. It clearly shows the problem.

The good news is that this isn't a bug, just an installation 
technicality :-): you need to tell the dynamic linker, where it can find 
the WCSLIB that is installed on your system. You can do this, by running 
the following command (after correcting `/path/to/wcslib' to the proper 
location on your system) before running `make check':

$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/path/to/wcslib

The fact that there were no complaints about other libraries, suggests 
that probably WCSLIB is installed in a different place compared to the 
rest of the dependencies.

To make this modification permanent in all future terminal instances, 
you can add the command above (without the `$') to your `~/.bashrc' 
startup file. This is also generically discussed in the "Known issues" 
section of the book (the first discussion of `make check' errors):

https://www.gnu.org/software/gnuastro/manual/html_node/Known-issues.html

This should fix the problem.

After no `make check' tests fail and you install Gnuastro, I recommend 
going through this tutorial to get a good feeling of all the basic tools 
that are available to you, culminating in proper usage of NoiseChisel):

https://www.gnu.org/software/gnuastro/manual/html_node/General-program-usage-tutorial.html

Here is a more complete explanation on the solution above:

All the failed tests complain about not finding the WCSLIB 
(`libwcs.so.5'). Here is one of them:

/home/lars/thesis/gnuastro-0.5/bin/mkprof/.libs/lt-astmkprof: error 
while loading shared libraries: libwcs.so.5: cannot open shared object 
file: No such file or directory

You were able to configure and build Gnuastro (when you ran 
`./configure' and `make -j8'). Therefore the compiler was able to locate 
WCSLIB when it was building the programs.

It is the dynamic linker that isn't able to find WCSLIB. The dynamic 
linker is invoked every time a program using dynamic/shared libraries is 
executed. The dynamic linker looks in paths specified in the 
`LD_LIBRARY_PATH' environment variable.

This is a thorny issue when dealing with dependencies, and I personally 
struggled a lot with it in my early days of moving to the free software 
world (after all, I am an astronomer, not a software engineer). So in 
the Gnuastro book, I have tried to explain them thoroughly.

To learn more about linking (and the differences between dynamic and 
static linking), you can see this page:

https://www.gnu.org/software/gnuastro/manual/html_node/Linking.html

To learn more about the installation directory and how the `*PATH' 
environment variables are used, please see this page:

https://www.gnu.org/software/gnuastro/manual/html_node/Installation-directory.html

After installing Gnuastro, you can also see these pages (and the whole 
Gnuastro book) on your command line (without needing an internet 
connection or taking your hands off the keyboard). Just run these 
commands (or just `info gnuastro' to start from the start of the book):

$ info gnuastro linking
$ info gnuastro "Installation directory"

Please don't hesitate to keep in touch regarding your thoughts on the 
programs and suggestions to improve it for future versions. To be 
informed of future versions, you can subscribe to this mailing list:

https://lists.gnu.org/mailman/listinfo/info-gnuastro

Cheers,
Mohammad