Why cross-compiling for ARM fails in ./configure?
arm, autoconf, cross-compiling, gcc, swi-prolog
Solution
The output of `configure` says:
checking for pthread support for cpu clocks... configure: error: in `(...)/pl-6.6.5/src':
configure: error: cannot run test program while cross compiling
What this probably means is that somewhere in `configure.ac` there's a call to the macro `AC_TRY_RUN` or something like it. This macro basically compiles an executable and executes it, trying to find out more details. Calling this macro won't work when cross compiling, since the build and host architecture differ. From your paste, there seems to be another one that doesn't cause `configure` to fail:
checking whether mutex support recursive locking... ./configure: line 7307: ./conftest: cannot execute binary file
IMHO package maintainers should be notified that their package won't cross compile (unless they specifically say that it won't in the `README` or other documentation).
In order to get it to cross compile, you have to figure out the "right" answers of the `AC_TRY_RUN` tests for your platform and find a way to integrate them into `configure.ac`, essentially patching `configure.ac`. The package maintainers might be able to assist with this task also.
I suppose you could also use something like Scratchbox2 if it's available for your device.
Problem
I know the question is vague, but I didn't quite know how to express what I'm facing here: I'm trying to cross-compile an implementation of Prolog (particularly SWI-Prolog) from the sources. They use the GNU-Autoconf tools (to which I'm a complete beginner) to build the sources, so I supposed I could set the `--host` and `--build` triplets to allow for ARM cross-compilation, but it didn't work. This is the command I issued: ``` $ ./configure --build=i686-pc-linux-gnu --host=arm-linux-gnueabi (... lots of checks ...) checking for clock_gettime in -lrt... yes checking for clock_gettime... yes checking for pthread support for cpu clocks... configure: error: in `(...)/pl-6.6.5/src': configure: error: cannot run test program while cross compiling See `config.log' for more details ``` (The complete output is pasted here) I've checked the config.log file, but I am unable to understand what's exactly missing. I understand that at this stage, there might be several missing libraries or errors, but I'm unable to understand where to start from.