How to prevent problems updating my LaTeX distribution (e. g. TeX Live / MiKTeX)

Question

I've been in this situation several times where I ran tlmgr update --all, wait for it to complete, and then my tex file refused to compile while giving some strange errors. AFAIK it usually caused by significant changes in packages, or packages being removed. Most of the time I had to spent hours of researching on the Internet to fix the problem. And more than often I issued the update command (and put myself in a bad situation) when I shouldn't (deadline is near or so).

My questions:

• How can I prevent similar problem from happen?

• And if it happens, how can I address which part of my tex file that causing problem as fast as possible?

• Or is there any reliable ways to restore my TeXLive distribution to its previous state? (Cuz running tlmgr restore --all often gave me some other weird errors, rather than get rid of them).

Answer 1

Although the question is very broad and three 15k+ users have commented, I still want to give it a try :).

First Approach

MiKTeX

• When you use MiKTeX then you can download an complete MiKTeX installation (see tutorial here for example).
• After the installation, you can easily store/save/archive the downloaded files and reuse them if you encounter problems after an update in the future.
• Instead of updating you can just repeat the process and you have a collection of MiKTeX snapshots.
• A complete MiKTeX download has about 2 GB which is only the quarter of a decent full hd movie :).
• I added a screenshot how the files look like.

TeX Live

• I do not so much about TeX Live -- I am not sure if there is a similar option as in MiKTeX to download a complete installation.
• But there are image files (ISO) which can also be easily stored and used in the case that an update causes problems.
• Here's the link to one of the sources of the image.
• Again, I added a screenshot that shows what I mean.

Second Approach

• Use a virtual machine like VMware or VirtualBox.
• Depending on the software/version you use, you can create so-called snapshots to which you can return after a bad update.
• You can also easily create copies of the virtual hard disk drives (often VMDK).
• In my experience, the performance of virtual machines is good enough.

Third Approach

• If you have access to more than one computer, then you can test the update on one of the computers first (on the less important one).
• If there are problems after the update, then you can try it again in a couple of days/weeks.

General Advice

I would recommend to not update your LaTeX system if some sort of deadline is near (e. g. less than 4-8 weeks) unless you need to.

In case you need to update something, I would rather update a single package (I mean the lowest number of packages that are needed in the specific case).

Such a case could be that you need a feature that was recently added to a package or that you need an update because there was a bug fix that is causing you (too much) trouble.

If possible just download the package from CTAN directly and place it relative to your LaTeX document so you can test it without actually installing it.

Answer 2

In the case of TeXLive, both Windows and Linux, it is possible to install as "portable" in the user's home folder, rather than in the program tree.

Then, an occasional zip archive can be used. For this to be manageable in size, you'd want to install without documentation and source code (grab individual documentation from the Internet when you need it, and store it elsewhere). You probably also want to avoid fonts that you'll never use.