Need help building GDC on 64-bit Debian

[Timo Sintonen]

I can not help you in this case, but this is a general problem in 
compiling gcc package, specially when making a cross compiler. 
The message is a bit misleading and is not related to the test 
which generates it.
Somewhere at the beginning, configure tests if it is possible to 
compile and link an executable program. If this fails, configure 
sets this variable telling that linking executables is not 
possible for this configuration. If some later test wants to test 
some feature by compiling and linking a test program, configure 
gives this error message. All tests would fail anyway, because it 
is not possible to make any kind of executable.
To make an executable we need headers, a working compiler, 
working binutils and working libraries for the target system. 
Even if the target system is the same ( I assume you are not 
making a cross-compiler) configure may give a different target 
name. In my Slackware the default configuration is 
x86_64-slackware-linux but the guessed configuration is 
x86_64-unknown-linux-gnu. Configure will not find all stuff for 
the guessed target and fails.
You have to look config.log at the directory make was when the 
error came. In somewhere near the beginning of the file there is 
something like "checking if gcc can produce executables" and you 
should look there what went wrong.
In my opinion configure should report an error and stop here, but 
I am not expert of that script either.