install directory is hardcoded

[danielb2]

I use ~/local for all my installs because it gets too cluttered otherwise. --prefix=$HOME/local otherwise I get ~/include ~/lib as well as ~/bin

However, in create_shortcut_cmd() I see the command path is hardcoded as sack__shortcut_cmd_path=~/bin/$sack__shortcut_cmd which obviously doesn't work for me.

Seems .sackrc would be a reasonable place to make this configurable?

[weakish]

Seems .sackrc would be a reasonable place to make this configurable?

Before install.sh runs, there is no .sackrc. Thus it is better to pass --prefix dir to install.sh.

[liuyang1]

Partly fix with my pull request.

not support "--prefix" yet, but could change or config it manually.