parallel: Warning: Finding the maximal command line length. This may take up to 1 minute.
So I wait a few seconds [snip]
This warning is only ever printed if running in Cygwin, not Linux or macOS or elsewhere. Cygwin is notoriously slow.
# This is slow on Cygwin, so give Cygwin users a warning
if($^O eq "cygwin" or $^O eq "msys") {
::warning("Finding the maximal command line length. ".
"This may take up to 1 minute.")
}
Also note that it only figures this out first time, after which it’s cached on disk.