title: How do you "echo" the last configure/make build --options within a source directory?
body: <p>When <strong>doing a a GNU-style " <em>./configure, make, and install</em></strong>  " - with specific  options, flags, etc...  As you all know, sometimes this can be a black art.. and what works for one piece of software may not for any other...</p>
  
  <p>Now, imagine that <strong>you had successfully built some package <em>XYZ.app</em> with some options</strong> like...</p>
  
  <p><code>% ./configure --with-1=2 USFLAG="-3 four" OBSCURE_LIB=l/lib/doihave</code></p>
  
  <p>and gone ahead and used it. Great. At a later point, <strong>you realize you need a previously omitted compile-time option, or maybe you've resolved a dependency issue, etc...</strong>  For whatever reason, you want to recompile this perfectly good binary.</p>
  
  <p>Now... <strong>how can you "recall" ALL of the options you passed</strong> to ./configure, verbatim, so as to use those SAME options, while possibly adding or subtracting some, this time around?</p>
  
  <p>I'm sure this stuff is buried somewhere in all those config.xxxx or AClocal or Makefile.xx files, but for the life of me, I haven'e been able to Google one straight answer.  </p>
  
  <pre><code>% file /usr/bin/$1 --&gt;  Mach-O 64-bit executable x86_64
  % ld /usr/bin/$1   --&gt;  -macosx_version_min not specificed, assuming 10.6
  % make -d          --&gt;  * 20 pages of Makefile nonsense.... *
  % ./config.log     --&gt;  * shows some history, but nothing interesting. *
  % ./config.status  --&gt;  * does a strange sequence oddly similar to a "clean" *
  % ./configure -h   --&gt;  * 500 options, none of which is "show-me=your-shit" *
  </code></pre>
  
  <p>glibtoolize, otool, autoconf, automake, pkg-config... all seem unwilling to help.
  One close-call seems to be the contents of the XYZ.pc file created by pkg-config..</p>
  
  <pre><code>prefix=/usr/local  \  exec_prefix=${prefix}  \  libdir=${exec_prefix}/lib
  includedir=${prefix}/include  \  Libs: -L${libdir} -lxyz-base 
  Cflags: -I${includedir} -I${includedir}/xyz
  </code></pre>
  
  <p>However, these just seem like environmental variables, not arguments from the actual config invocation...
  <strong>I'm sick of guessing... what is the real way to figure out the original build arguments, so that you can use them again, at will...?</strong></p>