You might want to consider running a full-text (grep) or file search on your mod folder for these common reasons: identifying which mod owns a specific item (by name alone), tracing Defs in error logs, or fetching details a troubleshooter requests from you while looking into your case. Especially in the latter scenario, a file search often is unavoidable to get information that can only be gathered in a feasible way on the users' computer.
Any OS has built-in tools for this process, but RimSort's file search adds RimWorld-specific tweaks for better investigations. Here's a quick guide to access and use it - assuming you know your search target or have been given precise instructions (including the ideal settings) by your troubleshooter.
While other mod managers - specifically; RimPy - offer the same feature, this guide will solely focus on RimSort as an example. RimPy's use is not recommended anymore for various reasons at the time of writing and other alternatives might be to situational either. We expect only advanced users to even know about them, so a simple guide like this one shouldn't be necessary for them to begin with. Our old guide for doing a file-search with RimPy can still be accessed in the Guide Archive if necessary though.
What to search for highly depends on the situation. If the log references defNames, search their exact strings - they appear identically in the game/mod files.
OS search tools typically only scan text- - or RimWorld-specific - .xml-files which contain said defNames. To also search through compiled code use a mod manager like RimSort instead, but the process is not as simple and might not succeed at all. This guide assumes you already know your target - or a troubleshooter specified it for you.
In the picture the Hugslog cites "Base81mmMortarShell" and "81mmMortarShellBaseCraftableBase" - search these exact references to ID their source. Ideally copy-paste the exact string if possible, to avoid typos!
Accessing the file search with RimSort is straight-forward. The menu is located in the "File Search"-tab directly in the main menu. It directly opens the tab which contains all file search relevant settings and aspects.
This screenshot shows the file-search window in RimSort according to version 1.0.52. Since the mod manager still receives considerable updates to its UI design though, this can easily change at any point. Just use common sense in the case our example becomes outdated.
Given the nature of the file search feature, it's hard to imagine anything changing too significantly though - aside from additional features/settings or a layout change.
A - Search Input
Your search-string (in our example: "Base81mmMortarShell") goes here.
B - Search Options
Some additional options for what or how RimSort does the search. Regex & case sensitivity can be ignore for most cases, xml-files only manages if the search should only go through those files or also include searching files like code assemblies. DefNames typically show in xml-files only and is most commonly used - often a troubleshooter will instruct you directly what to use or will assume to limit the search to only xml-files, which is considerably faster than with that setting turned off.
C - Search Range
Limits the search to active mods (includes base game files!), inactive mods, all mods or config files. The correct use should be obvious depending on whatever you search specifically. Usually you'd search through active mods only, but especially for modders, looking through all mods on their hard drive can be an useful tool.
D - Search Filters
These filters allow to limit the search results even further. For instance if you're searching for a defName that is suspected to be caused by a mod not updated properly against another mod's recent changes, putting "1.6" (or which ever the current version of RimWorld is at the time) would only show results from files within that mod's 1.6 version folder. This matters because in such a case the older versions of the mod would likely use the deprecated defName which is only considered outdated for the current update of the other mod. So finding it mentioned in any earlier version folder is simply expected and would probably be correct - only if it shows in the current version it would be considered outdated.
E - Start/Stop Search
Straight forward; starts the search process and can also stop (or pause) it again.
F - Results
If the search finds any use of the string searched, the results will show here. Listing the mod name the reference was found in, the name of the file, the exact file-path and further info. The file-path often also reveals which game version the file is meant for, in case you didn't limit the results with search filters. This can highly differ by how a mod's files are structured though, so you shouldn't completely rely on it.
G - Context Menu
Right-clicking any of the results offers you further options like to open the file directly (in your standard text-editor) or to open the folder the file is contained in - that way you can directly check the content of the files if necessary.
WIP