I cannot put any GregTech items into Storage Drawers.

I tested GregTech Steel Ingot, doesn't work.
Tested Industrial Craft Steel ingot, work just fine.

GT 5.10.6
SD 3.4.6

I'm currently having trouble testing this. GregTech is crashing out the creative menu in my dev environment. My hunch is it won't work in a deobfuscated dev environment. Normally obfuscated mods run fine, but this is getting snagged up on GT's use of Java 8 lambdas.

I don't suppose Greg publishes dev builds anywhere?

Didn't realize this was an unofficial fork, but I guess that's a good thing because I couldn't find any source behind Gregtech proper. I should be able to take this and build one myself, assuming there isn't a terrible dependency web to sort through.

1. GT5 is not Gregs, it is the Unofficial (but approved) fork of original GT5 (https://github.com/Blood-Asp/GT5-Unofficial/tree/1.10.2 - source)
2. No 1.10.2 dev builds anywhere I am afraid. Well there is one dev build for GT5.10.1, but cannot say how that build even works (https://onedrive.live.com/?id=478CC928A26B8E66%212853&cid=478CC928A26B8E66)

However I slice it, I can't get this working in my environment. When I built a source jar, Forge wouldn't recognize it as a mod jar (but it sure looks like one). If I try to pull it in as a module dependency, it pulls in a dozen more mods and fails to even start initializing.

What I can gather from running in a normal mod pack with SD's "debug logging" option enabled, right-clicking the drawers with GT items isn't activating my block's click handlers (or it's not invoking them with the primary hand, despite being held in the primary hand). This is probably on GT. You should open an issue on that project, linking this one.

Probably a gregtech issue. Gregtech's item class overrides the click handling since Greg uses the same item class for... well, pretty much every single item. So it's probably checking to see if the item is a foil or cover (so it can apply it to a machine or a pipe), then returning without setting the "event not handled - let somebody else do it" flag. Or however the exact dance goes.

AFAIK, click handling was changed a bit in 1.10.

A change was made in GT5-U for 1.10.2 that looks like it should fix this. I haven't tested it yet.