Overload resolution fails when one or more of the overloaded alternatives has a context function argument

[djneades]

Minimized code

def f(init: Int ?=> Int) : Int = 1
def f(s: String)(init: Int ?=> Int) : Int = 1

@main def main() =
  f((x:Int) ?=> x)

Output

Compilation with Dotty 0.27.0-RC1 fails with the following error:

[error] -- [E134] Type Mismatch Error: C:\Git\Overload\src\main\scala\Main.scala:5:2 ---
[error] 5 |  f((x:Int) ?=> x)
[error]   |  ^
[error]   |  None of the overloaded alternatives of method f with types
[error]   |   (s: String)(init: (Int) ?=> Int): Int
[error]   |   (init: (Int) ?=> Int): Int
[error]   |  match arguments ((Int) ?=> Int)
[error] one error found
[error] (Compile / compileIncremental) Compilation failed

Expectation

Compilation should succeed, with the method call in main being resolved to f(init: Int ?=> Int).

Note that compilation succeeds if the second definition of f is removed.

Additional test cases

The following code, where only one of the overloaded methods has a context function argument, also fails to compile:

def f(init: Int ?=> Int) : Int = 1
def f(s: String) : Int = 2

@main def main() =
  f((x:Int) ?=> x)

[error] -- [E134] Type Mismatch Error: C:\Git\Overload\src\main\scala\Main.scala:5:2 ---
[error] 5 |  f((x:Int) ?=> x)
[error]   |  ^
[error]   |  None of the overloaded alternatives of method f with types
[error]   |   (s: String): Int
[error]   |   (init: (Int) ?=> Int): Int
[error]   |  match arguments ((Int) ?=> Int)
[error] one error found
[error] (Compile / compileIncremental) Compilation failed

Note too that the following slightly more complex code (more representative of what I was actually trying to use) also similarly fails to compile:

def f(init: Int ?=> Int)(using i : Int) : Int = init
def f(s: String)(init: Int ?=> Int)(using i : Int) : Int = init

@main def main() =
  given Int = 10
  f((x:Int) ?=> x)

[error] -- [E134] Type Mismatch Error: C:\Git\Overload\src\main\scala\Main.scala:6:2 ---
[error] 6 |  f((x:Int) ?=> x)
[error]   |  ^
[error]   |  None of the overloaded alternatives of method f with types
[error]   |   (s: String)(init: (Int) ?=> Int)(using i: Int): Int
[error]   |   (init: (Int) ?=> Int)(using i: Int): Int
[error]   |  match arguments ((Int) ?=> Int)
[error] one error found
[error] (Compile / compileIncremental) Compilation failed

[djneades]

I have updated the description with an additional, even simpler, test case. I have also updated the issue title to reflect that the problem is more significant than I had initially realized.