Valve added an invisible wall to this sewer pipe in Half-Life 2 in their anniversary update - but it only annoyed speedrunners

rockpapershotgun.com:

Half-Life 2 just got a small update, mostly to fix a long-running music bug. But hiding in the patch notes is an apology of sorts, a nod to that most tenacious of bunnyhopper: the Half-Life 2 speedrunner. It seems the recent 20th anniversary update for the classic first-person shooter messed with some beginner speedrun strategies by introducing an invisible wall to a big sewer pipe. Valve have now corrected that, removing the offending blocker and restoring order to the universe. Well, almost.

"Removed collision from an underwater tube that speed runners enjoy," write the developers in the update post, with traditional Valve inscrutability. They're talking about a large pipe in the sewers of the Route Kanal sequence, which you've got to flood with water to pass through (you can see said pipe in this playthrough). It seems Valve always intended for this pipe to have a big "player clip" over it - an invisible wall you can see in the map editor image below. The clip would be set to vanish once you solve the puzzle by turning a nearby valve to flood the room.

Yet, for whatever reason, this invisible wall was previously only present in the Xbox 360 version of the game, according to speedrunners at SourceRuns, who've been diligently tracking recent changes to the game. PC players have always been able to indulge in the speedrunning act of skipping the puzzle by, say, glitchily clambering up the wall with a barrel. Oh, you clever little speedos.

But the anniversary update two weeks ago "fixed" the original oversight by plopping the wall into the PC version too. As you can imagine, this made the usual speedrun trick impossible.

It's only one example of the many changes that make the anniversary update a no-go for the most furious of fastbois. Plenty of other bug fixes have effectively confiscated an arsenal of glitches that speedrunners use to zip through the game. One such nerfed trick is called the "Item Save Glitch" which I won't explain in detail but basically allows