Regression in lichess/lila during access to contextual member in Tuple arrow

[WojciechMazur]

Based on the OpenCB failure in lichess/lila

Compiler version

Last good release: 3.10.0-RC1-bin-20260630-a8ae375-NIGHTLY
First bad release: 3.10.0-RC1-bin-20260701-14f4239-NIGHTLY
Bisect points to 4f67b39

Minimized code

class Context(val lang: String)

inline def ctx(using it: Context): Context = it

def test(xs: List[Int])(using Context): List[(Int, String)] =
  xs.map(tid => tid -> ctx.lang)

Output

❯ scala compile ../community-build3/test.scala -S 3.nightly --server=false
-- Error: /Users/wmazur/projects/scala/community-build3/test.scala:13:13 -------
13 |  xs.map(tid => tid -> ctx.lang)
   |         ^^^^^^^^^^^^^^^^^^^^^^
   |         cannot establish a reference to Context#lang
1 error found

Expectation