You don't want to use eval(BLOCK) though. The block is compiled at the surrounding's compile-time. You want eval(EXPR).

Compare this:

#!/usr/bin/perl -l
print 'pre';
eval { BEGIN { print 'compiling eval block' } };
print 'post';
[download]

with this:

#!/usr/bin/perl -l
print 'pre';
eval q{ BEGIN { print 'compiling eval expr' } };
print 'post';
[download]