cross compiling gsl for arm cortex M4 (nrf52)

[Julius Duin]

Hi,
I am currently working on adding some curve fitting algorithm to an embedded 
application of mine. For this reason I want to use the gsl multifit nlin 
module. I have already written and tested such an application on my mac, 
everything works well and fits my needs entirely. 
Though now comes the tough part, cross-compiling the library to use it in an 
embedded project. I have the gsl src code on my machine, downloaded from here: 
https://ftp.gnu.org/gnu/gsl/ and am trying to configure it with some help I 
found here: 
https://stackoverflow.com/questions/70886508/how-to-crosscompile-gsl-for-arm-cortex-m4
 the configuration works fine but running make check runs into an error like 

minmax.c:26:10: fatal error: gsl/gsl_minmax.h: No such file or directory
   26 | #include <gsl/gsl_minmax.h>
      |          ^~~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [minmax.lo] Error 1
make: *** [check-recursive] Error 1

and running make runs into problems in the siman module. So I guess something 
must be wrong with my configuration, maybe someone has experience with this 
kind of process?
the configuration is: 

./configure CC=/usr/local/gcc/bin/arm-none-eabi-gcc 
CXX=/usr/local/gcc/bin/arm-none-eabi-gcc 
LD=/usr/local/gcc/bin/arm-none-eabi-gcc AR=/usr/local/gcc/bin/arm-none-eabi-ar 
OBJCOPY=/usr/local/gcc/bin/arm-none-eabi-objcopy CFLAGS="-mthumb 
-march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=soft" CXXFLAGS="-mthumb 
-march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=soft" LDFLAGS="--specs=nano.specs 
--specs=nosys.specs -mthumb -march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=soft" 
--target=arm-none-eabi --host=arm-none-eabi

My first attempt of using the library in an embedded project was to just add 
the include path and piece by piece add the src code files but this obviously 
ran into many many problems on its own. 
My goal is to have a single libgsl.a file (and libgslcblas as thats needed as 
well I suppose) and just add it to my project like that. 

Hopefully someone can help, Id be grateful!
Best

Julius