Re: [gentoo-dev] Calling unknown commands in an ebuild

[Mike Frysinger]

On Sunday 07 February 2010 16:10:10 Stelian Ionescu wrote:
> Wouldn't it be a good idea to use "set -e" in the ebuild environment ?
> I've seen cases of ebuilds calling epatch without inheriting from eutils
> which compiled and installed (apparently) fine but possibly broken
> binaries.

this is not the way to approach the problem.  'set -e' has a lot of 
implications people don't realize.  _any_ command that exits with non-zero 
will break things.  such as:
	matches=`grep foo ./some-file`
no matches of 'foo' will cause the ebuild to exit immediately.  it doesnt take 
much effort to find plenty of other examples.

it also valid to try and do something like `foo --version >& /dev/null` as a 
naive test to see if a program exists and works.  messing with the fundamental 
'command not found' behavior may unintentionally break this.

> https://bugs.gentoo.org/buglist.cgi?quicksearch=command+not+found
> and perhaps others I haven't managed to find in bugzilla

many of those would still fail with `set -e` in the ebuild environment because 
the missing command is run through a build system like makefiles.
	ebuild -> make -> shell -> no command found
-mike