t/harness Finer diagnostics from test suite
t/io/argv.t See if ARGV stuff works
t/io/dup.t See if >& works right
+t/io/fflush.t See if auto-flush on fork/exec/system/qx works
t/io/fs.t See if directory manipulations work
t/io/inplace.t See if inplace editing works
t/io/iprefix.t See if inplace editing works with prefixes