sh: 50: //tmp/choosenim-0.3.2_linux_amd64: not found
Looks like a bug in the install script adding double slashes.
```
root@1df60238e2ab:/tmp# curl https://nim-lang.org/choosenim/init.sh -sSf | sh
choosenim-init: Downloading choosenim-0.3.2_linux_amd64
sh: 50: //tmp/choosenim-0.3.2_linux_amd64: not found
root@1df60238e2ab:/tmp# ls /tmp
choosenim-0.3.2_linux_amd64
root@1df60238e2ab:/tmp#
```