[OS X TeX] Bug in Preference Pane

[Richard Koch]

Jerome and TeX Users,

Unfortunately, there is a significant bug in the Preference Pane, build 151, which is
installed by MacTeX-2011 and BasicTeX. This version of MacTeX will be on the DVD,
so we will be living with this bug for some time.

Because of the bug, users who install TeX Live 2011 will not be able to switch back 
to an earlier distribution like TeXLive-2010 or TeXLive-2010-64.
The Preference Pane will see the distribution and appear to select it,
but the user's front end will complain that there are no TeX binaries
in that location.

(If you installed a beta version of TeX Live 2011, you may not see the problem.)

MacTeX does not touch the TeX Distribution Data Structures from earlier distributions,
but the Preference Pane does, when it first selects an old distribution. The Pane
writes a symbolic link named "texbin" in the data structure's Programs folder.
Unfortunately, build 151 of the Pane writes an incorrect value for this link.

Once you know more details, your inner geek will be able to fix the problem.

Using Terminal, 

	cd /Library/TeX/Distributions/.FactoryDefaults
	ls

You will see a lot of folders, one for each TeX distribution. There will be folders 
for some distributions you do not have, but that is fine.

One folder you will certainly have is TeXLive-2011. Type

	cd TeXLive-2011/Contents/Programs
	ls

to see the files in the Programs folder for this distribution. You will see five
entries. Four will be links named i386, ppc, powerpc, and x86_64
pointing to the locations of binary directories for various kinds of processor. These
are fine. Then you will see texbin, and it will be a link to one of these other links.
On my Lion machine, texbin points to x86_64. I believe that everyone will have
a reasonable value for texbin.

Now examine one of the other distributions, say TeXLive-2010. In Terminal type

	cd /Library/TeX/Distributions/.FactoryDefaults
	cd TeXLive-2010/Contents/Programs
	ls -l

If you have already selected TeXLive-2010 in the new Preference Pane, you will
see four links. Three, named i386, ppc, and powerpc, will be fine, pointing to
various binaries in the distribution. But texbin will point to universal-darwin,
which is not one of the choices. To fix it, type

	sudo rm texbin
	sudo ln -s i386 texbin

If you have a PowerPC machine, use powerpc rather than i386 in this last command.

Repeat this process for TeXLive-2010-64

	cd /Library/TeX/Distributions/.FactoryDefaults
	cd TeXLive-2010064/Contents/Programs
	ls -l

You will see links named i386, powerpc, and ppc, which are fine. But texbin 
will be a link to x86_64, which doesn't exist. It should instead be a link to i386. So

	sudo rm texbin
	sudo ln -s i386 texbin

If you have other older distributions, you will have to fix them in the same way. Once
fixed, build 151 of the Pref Pane won't break them.

Dick Koch