Working on an old Linux (Ubuntu 16.04) server I realized I had nim 1.2.x installed, so I checked if choosenim was available.

It was (couldn't check the version) so I tried

choosenim update self
...
   Updating choosenim
[##################################################] 100.0% 0kb/s
      Info: Updated choosenim to version 0.8.4

but then invoking choosenim:

$ choosenim
could not load: libcurl.so(|.4)
(compile with -d:nimDebugDlOpen for more information)

(sudo apt-get install libcurl4-gnutls-dev fixed the problem, but I was intrigued by the fact that choosenim was working before the update, so it might be worth a check ...)