Fix macos install (#67)

* update shell path and some docs

* download ADB if not present

* big O not little o

* bugfix

* bugfix

* silence errors for macos developers

* Update dist/install-common.sh

Co-authored-by: Will Greenberg <willg@eff.org>

---------

Co-authored-by: Will Greenberg <willg@eff.org>

rootshell/src/main.rs

@@ -6,6 +6,7 @@ use std::process::Command;
 use std::os::unix::process::CommandExt;
 use std::env;
 
+#[cfg(target_arch = "arm")]
 use nix::unistd::Gid;
 
 fn main() {
@@ -14,11 +15,13 @@ fn main() {
    // Android's "paranoid network" feature restricts network access to
    // processes in specific groups. More info here:
    // https://www.elinux.org/Android_Security#Paranoid_network-ing
+   #[cfg(target_arch = "arm")] {
    let gids = &[
       Gid::from_raw(3003), // AID_INET
       Gid::from_raw(3004), // AID_NET_RAW
    ];
    nix::unistd::setgroups(gids).expect("setgroups failed");
+   }
 
    // discard argv[0]
    let _ = args.next();