Issue #72 describes the same problem. I have just done some tests and compared between gsc from the installer and HomeBrew

Ok here is the error message :

The full verbose (gsc -verbose test.scm)
Parsing:
  fact-aux
  fact

Compiling:
  fact-aux
fact

Dumping:
  #<primitive | test|>
  #<procedure fact-aux>
  #<procedure fact>

Compilation finished.
gcc -arch x86_64 -m64 -arch x86_64 -m64  -bundle  -Wno-unused -Wno-write-strings -O1 -fno-math-errno -fschedule-insns2 -fno-trapping-math -fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common -mieee-fp   -flat_namespace -undefined suppress  -D___SINGLE_HOST -D___DYNAMIC -I"/Library/Gambit-C/v4.7.2/include" -o "test.o1"   test.c 
clang: error: unknown argument: '-fschedule-insns2' [-Wunused-command-line-argument-hard-error-in-future]
clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
*** ERROR IN ##main -- C compilation or link failed while compiling "test.scm"

Here is the code:
;(standard-bindings) (extended-bindings) (block))
(define (fact-aux n a)
  (if (<= n 1)
      a
      (fact-aux (- n 1) (* a n))))

(define (fact n)
  (fact-aux n 1))

**************************************************
Then I reinstalled the HomeBrew gambit and I got this :

Parsing:
  fact-aux
  fact

Compiling:
  fact-aux
fact

Dumping:
  #<primitive | test|>
  #<procedure fact-aux>
  #<procedure fact>

Compilation finished.
clang    -bundle  -Wno-unused -Wno-write-strings -O1 -fno-math-errno -fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common   -flat_namespace -undefined suppress  -D___DYNAMIC -I"/usr/local/Cellar/gambit-scheme/4.7.2/include" -o "test.o1"   test.c 

************************** to compare with (from the installer)
gcc -arch x86_64 -m64 -arch x86_64 -m64  -bundle  -Wno-unused -Wno-write-strings -O1 -fno-math-errno -fschedule-insns2 -fno-trapping-math -fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common -mieee-fp   -flat_namespace -undefined suppress  -D___SINGLE_HOST -D___DYNAMIC -I"/Library/Gambit-C/v4.7.2/include" -o "test.o1"   test.c 

***************************************************

To my surprise the HomeBrew gsc uses clang and not the gcc-4.2 though it was given the path at installation.

Same gambit versions but different command lines !!!!!

-fschedule-insns2 seems to be one part of the problem

Thanks,

Denis

> Subject: Re: [gambit-list] macos 10.9
> From: feeley@iro.umontreal.ca
> Date: Mon, 5 May 2014 12:50:04 -0400
> CC: gambit-list@iro.umontreal.ca
> To: denis.prog@hotmail.com
>
>
> On May 5, 2014, at 12:34 PM, Denis Fourt <denis.prog@hotmail.com> wrote:
>
> > Hi,
> >
> > I tried to install gambit with the installer. The interpreter worked, the compiler failed to compile a simple file (xcode and its command lines tools were installed). I finally installed apple's old gcc4.2 and then gambit with HomeBrew (the gambit formula allows to specify a compiler) and it seems to work fine. Well I might get some problems when linking with some 10.9 libs, I have no idea whether apple's previous and present compilers produce compatible binaries or not.
> >
> > Any thoughts, similar troubles related to this topic?
> >
> > Thanks,
> >
> > Denis
>
> Can you open an issue for this on github? (https://github.com/feeley/gambit/issues)
>
> It would help if you could give the error messages that were produced. You should try to call gsc with the -verbose option so that the invocations of the C compiler are shown.
>
> Marc
>