When I played with blackhole's "bh install" command in osx, it stops at "Downloading packages".
After I look into the source code, it seems the call to "with-output-to-process" in "untar" function causes this.
Below are code I wrote to reproduce the problem
(with-output-to-process
(list path: "sed"
arguments: '("-e" "s/n/N/g"))
(lambda ()
(display "nothing")))
--
Zhang Meng
School of Software Engineering, Tongji University
MP: +86 151-2103-2798