Tool for debugging makefiles

Question

I have a large legacy codebase with very complicated makefiles, with lots of variables. Sometimes I need to change them, and I find that it\'s very difficult to figure out

Answer 1

From the man page on make command-line options:

-n, --just-print, --dry-run, --recon  
Print the commands that would be executed, but do not execute them.  

-d  Print debugging information in addition to normal processing.  
The debugging information says  
which files are being considered for remaking,  
which file-times are being compared and with what results,  
which files actually need  to  be  remade,  
which implicit  rules are considered and which are applied---  
everything interesting about how make decides what to do.  

--debug[=FLAGS] Print debugging information in addition to normal processing.  
If the FLAGS are omitted, then the behaviour is the same as if -d was specified.  
FLAGS may be:  
'a' for all debugging output same as using -d,  
'b' for basic debugging,  
'v' for more verbose basic debugging,  
'i' for showing implicit rules,  
'j' for details on invocation of commands, and  
'm' for debugging while remaking makefiles.