There are a few caveats which bear mentioning when using mods on native versions of Borderlands 2/TPS under Linux and Mac.

• Linux/Mac: Game Patching
• Linux/Mac: Run Mods From The "Title" Screen!
• Linux: Case-Sensitivity Issues
• Linux/Mac: DLC Directory Ordering Issues
• Linux: Problems with connecting to SHIFT
• Linux and Mac: Bypassing the Sanity Check

Note: The info on this page basically only applies if you're running the actually-"native" versions on Linux and Mac, as ported by Aspyr. It's recommended you use the Windows versions whenever possible, instead!

Linux users are strongly encouraged to use the Windows version of BL2/TPS, via Wine/Proton, rather than the outdated native ports. That will also permit you to install PythonSDK, which will take care of enabling text-based mods for you. Mac users are encouraged to do the same, too, though we've never gotten much feedback from Mac users on exactly how to do that.

If you want information on the legacy hex edits which have been used in the past, see the Hex Edits page -- you'll need to fire up a hex editor and take care of them yourself.

Windows users are able to run mods from the main menu, but the Linux (and Mac) ports work a little differently, and it won't actually work properly if you try from there. Instead, you need to do it from the "Press any key" screen, which just has the Borderlands logo and that phrase. Complicating matters slightly is that you do have to go into the main menu first, in order to have all the DLC content loaded and available for patching. So, in order to execute mods when first starting up, this is the procedure:

1. When you get to the "Press any key" screen, hit a key to go to the main menu
2. Once at the main menu, wait for a few seconds for the game to establish a connection to Gearbox. In BL2, you may see a very slight glitch in the character animation when that happens. In TPS, there's actually some text notifications letting you know that it's attempting the connection, and another message once it succeeds/fails.
3. Hit Esc and then "Yes" to get back out to the Title screen.
4. From there, you can pull down the terminal and exec patch.txt to load your patches.

If you need to re-execute any patches or anything later, be sure to go all the way back out to the title screen again.

When you type exec <filename> at the console to load up a patch file, on Linux the engine will automatically convert the filename to all-lowercase, so the patch you're trying to execute must have an all-lowercase filename to match. This can be somewhat confusing, since the error message you'll see at the console will retain the case as you typed it in, rather than the lowercase version.

Since FilterTool/BLCMM both expect the default filename to be Patch.txt (with a capital "P"), one way to make everything happy is just to create a symlink in your binaries dir, like so:

lrwxrwxrwx  1 pez pez        9 Feb  9 16:55 patch -> Patch.txt
-rw-r--r--  1 pez pez  3520596 Feb 28 20:48 Patch.txt

That way, FT/BLCMM can continue to use Patch.txt for the filename, and you'll be able to just type exec patch from the console to load your patches.

NOTE: OSX's historical filesystem, HFS+, does not have this problem but starting with 10.13/High Sierra, APFS is starting to be used, and that does appear to have the same problem that Linux users have. If anybody has experience setting up alternate mountpoints in macOS, let us know (or edit this page) to let us know how to address it on those platforms.

This is a rather bizarre issue, due to some cross-platform differences between Windows and Linux, and because of some behaviors of the Borderlands engine. It's worth noting that this issue doesn't actually affect much - you'll miss out on some statements which modify gun parts, mostly - so don't sweat it if you don't want to deal with this.

Basically, when looking for DLC on your hard drive, Borderlands looks inside the steamassets/dlc directory and loads the mods in the order they're given by the kernel. On Windows, the filesystem driver will return the directories in alphabetical order by default. On Linux, the order of the directories is effectively random. (When looking at a directory listing via ls on Linux, the ls command does the sorting for you. If you want to see the "native" order in which the directory entries are given, you can run "ls -U" or "ls --sort=none".)

As the engine loads these DLC, some of the property names get dynamically-assigned number suffixes, and the numbers depend on what order the DLC is loaded. Mods which try to edit these values need to hardcode a number to use -- any mod written/tested on Windows is going to be using the numbers you get by sorting the directories alphabetically. For instance, the internal part list collection for one class mod from the Dragon Keep DLC has this property name:

GD_Aster_ItemGrades.ClassMods.BalDef_ClassMod_Aster_Assassin:ItemPartListCollectionDefinition_28

However, the last number could easily be something else, like:

GD_Aster_ItemGrades.ClassMods.BalDef_ClassMod_Aster_Assassin:ItemPartListCollectionDefinition_42

And on other Linux systems it could be something different. There's no way to actually predict what number it'll be. This doesn't have a super wide impact, since there aren't that many mods which actually touch these variables, but UCP does contain a few statements which do, and you'll risk not getting the full effect of some mods.

Unfortunately, the only real fix for this is to mount your Borderlands DLC directory under a separate filesystem which supports sorting directories alphabetically. No native Linux filesystem does this. It's possible to disable some features on an ext4 filesystem, so that directory entries will be given in the order in which they were created. So theoretically you could create an ext4 partition, use the following tune2fs command on it:

# tune2fs -O ^dir_index /dev/foo

... and then carefully copy the DLC directories into that filesystem, one at a time, in alphabetical order. That method seems quite fragile to me, though, and I wouldn't recommend that even though you'd still be using a native Linux FS.

What I've done on my own system is to just resign myself to using NTFS. The Borderlands 2 DLC dir contains a little over 6GB of data, so I created a new 10GB LVM LV, used "mkfs.ntfs /dev/vg/bl2dlc" (obviously substitute the proper device name there), copied over all the DLC data into that new filesystem, and then added the following to my /etc/fstab -

# Borderlands 2 DLC Modding Nonsense
/dev/mapper/vg-bl2dlc  /usr/local/games/Steam/SteamApps/common/Borderlands\0402/steamassets/dlc   ntfs    uid=1000,gid=1000,umask=022   1 2

Note the special string "\040" in the pathname, required because there's a space in the directory name. Adjust the device name, path, UID/GID/umask, etc, to suit your circumstances. Make sure that the dir is mounted properly and that the DLC data is in there, and you should be good to go. You can use "ls -U" in the DLC directory to verify that they're showing up in alphabetical order now.

So... yeah. That is quite weird, and I suspect not a lot of folks are going to be willing to do something like that to their system, just to support some game mods. Still, if you're looking for 100% mod compatibility inside Linux, this is a step you'll have to deal with.

On some distros (Arch Linux for example), SSL sertificates is stored in /etc/ssl rather than /usr/lib/ssl. This will cause problems while connecting to SHIFT. Simple solution is to create a symlink: ln -s /etc/ssl /usr/lib/ssl But it can cause troubles, so the best way to handle this is to launch game with SSL_CERT_DIR=/etc/ssl/certs. Source: https://wiki.archlinux.org/index.php/Steam/Game-specific_troubleshooting#Logging_into_SHiFT

This actually affects Windows as well. When Borderlands loads a savegame, it runs all the weapons and items in the savegame through a "sanity check" to make sure that the items are valid. If an item/weapon is discovered which fails the check, it is silently removed from your inventory. If you don't notice at the time and the game saves over your game, you'll have lost that item. (Hitting Alt-F4 to force-quit the game would prevent overwriting your save, if you notice in time.)

Some Borderlands mods will create items which would otherwise run afoul of this sanity check. So long as you remember to execute the patch/mod before continuing the game from the main menu, the sanity check won't touch your modded weapons, but it's easy to occasionally forget to execute the mod before actually loading the game, which could lead to lost items. So, the solution is to disable these checks!

For Windows users, c0dycode has created a Hex Multitool utility to handle hex-editing this sanity check out (among other tweaks). He's also got a Borderlands Mac and Linux Stuff page with information on hex-editing on Mac and Linux, along with a little Python script to automate it for you.