do_install fails because of missing DESTDIR

[olafmandel]

do_install() fails because it tries to write to the root directory.

At least on my system, it is not possible to locally set an environment variable on the command line calling a Bash function (like do_install() does). Example:

#!/bin/sh

a() {
    sh -c 'echo bar=\"$bar\"'
}

b() {
    sh -c 'echo baz=\"$baz\"'
}

foo=123 sh -c 'echo foo=\"$foo\"'
bar=456 a
export baz=789
b
$SHELL --version | head -1

Output:

foo="123"
bar=""
baz="789"
GNU bash, version 4.2.37(1)-release (x86_64-pc-linux-gnu)

So setting a variable locally before calling a "real" command works (foo) and setting a variable globally before calling a function works (baz). But setting a variable locally before calling a function fails (bar).