Re: Bug#310872: zsh can't be a ksh replacement (can't trap ERR).

[Clint Adams <schizo@debian.org>]

> Why not add ash, dash, bash and so on, into the ksh pool, until
> only "a=foo" and "echo bar" are the common points ? surely because
> all of us have an idea of what ksh should be, only this idea is a
> bit different for each of us.

None of those shells purport to emulate ksh.  zsh does.

> I realize there are many differences between implementations of
> shells. There must be some incompatibilities between pdksh and ksh.
> But this trap ERR thing seems to be a basic ksh functionnality.

I don't have enough knowledge of ksh to evaluate that statement.

> Last, zsh is such a special shell, with all its exotic and powerful
> functionalities, that when you need/want it, it is unlikely
> you want it as a ksh. Debian already have 2 ksh...

The zsh alternative was suggested by the Debian ksh93
maintainer.

> I definitely hope that the alternative will be removed...

It's not a high-priority alternative.  That means that it won't be
selected automatically over either pdksh or ksh93.  One would need
to either only have zsh installed or override the defaults.  Since
the Debian zsh package is frozen for a June 6 release, the severity
of your problem will not justify a change to the package.

After that, we can do one of three things: leave things the way they
are; remove the alternative; patch the source or cause zsh to understand
the ERR pseudo-signal within ksh emulation in another manner.

If the wise people on zsh-workers think that not understanding ERR is
acceptable for ksh emulation, I'm inclined to do nothing.