Upgrade from TeX Live 2017 to 2018

By default, please get the new TL by doing a new installation instead of proceeding here.

That is, you should have a specific reason to do an upgrade instead of a new install, and you should be familiar with Unix and TeX Live. If you have any doubts whatsoever, please do a new installation.

We do not provide a dedicated upgrade script. The procedure here is not bullet-proof, or recommended; consider it provided as-is, to be used at your own risk, if you want to do so, for reasons of your own. It's your responsibility to understand what is being done. Failing any of that, please do a new installation.

These instructions say nothing about what is done as root or as a normal user; that's because TeX Live installations are done both ways (root is not required for anything in TL itself), and we can't know which you chose. You need to know. If you don't, do a new installation.

It's not possible to upgrade to TL'18 from TL'15 or earlier.

Unix

1. Find the parent directory of the current installation; it's /usr/local/texlive by default.

2. Copy the whole directory 2017 to 2018, preserving symbolic links; for example:
   cp -a 2017 2018
   If you don't understand this, stop here and do a regular installation.

3. To save some space, you can exclude tlpkg/backups/* or remove them from the 2018/ directory afterwards. (Theoretically, you could rename 2017 to 2018, but we strongly advise against this, since you may lose your existing installation with no good way back.)

4. If you installed symlinks in system directories (via the installer option or tlmgr path add), remove them now with tlmgr path remove.

5. As needed, adjust your PATH in your startup files to point to .../2018/bin/platform instead of .../2017/....

6. Log out and log in, and confirm that your PATH now has the 2018 directory. This is crucial. Your PATH must use the new location.

7. cd to your top-level .../2018 directory.

8. Download the latest update-tlmgr-latest.sh and run it like this:
   sh update-tlmgr-latest.sh -- --upgrade
   (The extra options are to try to prevent the upgrade from happening unintentionally.)

9. If you don't want to use the default repository (that is, not the automatic CTAN redirection) for downloading the new files, run (as usual):
   tlmgr option repository yourrepo

10. Run (with patience, it will be downloading all the new material):
    tlmgr update --self --all

11. Remake the lualatex/fontspec cache:
    luaotfload-tool -fu

12. If you want symlinks in system directories (not recommended), run tlmgr path add.

13. When you are happy with how the new TL is working, if you wish you can remove the old installation by running .../2017/.../tlmgr uninstall (full tlmgr doc). Not recommended, since you might always find a document that doesn't work with the new version, just at the wrong time …

Good luck, and to reiterate from the top, don't do any of this if it doesn't make sense to you. Just do a fresh installation.

Windows

There is no comparable upgrade procedure for Windows. Doing a new installation is necessary.