Bash is not expanding the ~ character in the argument `--home_dir=~`. For example:

```
$ echo --home_dir=~
--home_dir=~

```

Bash does expand ~ when I leave out the hyphens:

```
$ echo home_dir=~
home_dir=/home/reedwm

```

Why does Bash have this behavior? This is irritating, as paths with ~ are not expanded when I specify that path as an argument to a command.