bug#20903: aclocal failure when installed to prefix containing '@'

[Eric Bavier]

Hello Automake devs,

I have automake version 1.14.1 installed to a prefix containing the '@' 
character.  Perl version 5.10.0.  Running aclocal (through 
'autoreconf'), I get the following warnings, then failure:

Possible unintended interpolation of @4 in string at 
/ptmp/bavier/projects/spack/opt/unknown_arch/address@hidden/address@hidden/bin/aclocal 
line 72.
Possible unintended interpolation of @1 in string at 
/ptmp/bavier/projects/spack/opt/unknown_arch/address@hidden/address@hidden/bin/aclocal 
line 72.
aclocal: error: couldn't open directory 
'/ptmp/bavier/projects/spack/opt/unknown_arch/gcc.3.4/automake.14.1-56e69c6c/share/aclocal-1.14': 
No such file or directory
autoreconf: aclocal failed with exit status: 1

This seems related to perl's array interpolation in strings.  Line 72 
contains:

my @automake_includes = 
("/ptmp/bavier/projects/spack/opt/unknown_arch/address@hidden/address@hidden/share/aclocal-$APIVERSION");

Replacing the '@' characters with "\@" lets aclocal run without error.

`~Eric