Mysts attempt to keep a giant wall of text to a minimum.

Just to add another little bit there.

-mtune=native is an invalid switch. -march=native is the correct switch in that context. You do not specify it unless you are cross-compiling the code to be run on another machine or for another very specific reason. The default is to compile for the machine the compiler is running on anyway.

Run the configure script and it will create a total of four makefiles. One in the current folder, one in the m7 sub-folder, one in the compat sub-folder and one in the compat/jansson sub-sub-folder. The makefiles are all called Makefile.[nothing] so open each one in turn with an ordinary text editor and just replace all instances of the string -fuse-linker-plugin with nothing and remove one of the resulting extra spaces at the same time, then save the makefile. Then use the command make clean (to clear out any shit from a previous run) and then use make. It will compile.

Do not bother with the makefile.am file. That, the autogen script and the resulting configure script are riddled with bugs. I found that any flags you specify against the configure command are ignored (took me a while to realize that) and if you want flags to be used then you have to edit them directly into the makefiles. Nothing else works properly. It is a right bloody kerfuffle, but when you know what you are doing it can be sorted out and corrected.

So ... you have already run autogen and configure. Edit the four makefiles. Run make clean. Run make. You should now have a minerd.exe to play with.