On 2009-11-23, Uwe Stöhr wrote:
> > - if (mustProvide("mhchem"))
> > + if (mustProvide("mhchem") && isAvailable("mhchem"))
> It is not that easy.
...
> Your solution does nevertheless not help because mhchem wouldn't be
> loaded when it is not available. But in this case LaTeX cannot install
> this missing package. The nice feature with recent LaTeX distribution
> is that LaTeX will automatically install missing LaTeX-packages that
> are in the TeX file you are compiling.
Not all users have or like this auto-install feature. Especially on a
multi-user system it would either require you to become root
(Administrator) or do a private install (i.e. download the package
again if another user needs it).
> Moreover, you would get different LaTeX output when exporting the LyX
> file on different computers. This makes collaboration extremely
> insufficient because the user without mhchem doesn't even get an
> information why his PDF and LaTeX output looks different than on
> another PC.
This is why I vote for providing mhchem support in form of a module.
This makes it very explicit (opt-in instead of opt-out) whether the
package should be used.
Günter
