Chatterino2 overlay causing qmake problem

I’m trying to use an overlay that simply updates the fetchFromGithub used in the chatterino2 package. The package can be installed successfully when fetching the current and older chatterino2 versions, but when trying with its recent v2.4 it cannot complete due to some issue with qmake at the package’s configurePhase. It seems the command generated to execute qmake isn’t understood, and it just spits out the help text?

@nix { "action": "setPhase", "phase": "qmakePrePhase" }
qmakePrePhase
@nix { "action": "setPhase", "phase": "qtPreHook" }
qtPreHook
@nix { "action": "setPhase", "phase": "unpackPhase" }
unpacking sources
unpacking source archive /nix/store/9gsxvizq1hvczydq4qnzg4ni6rjl8swn-source
source root is source
@nix { "action": "setPhase", "phase": "patchPhase" }
patching sources
@nix { "action": "setPhase", "phase": "configurePhase" }
configuring
QMAKEPATH=/nix/store/qg7j3q408ymjyw40lljqmq41a4pq6qhc-qtbase-5.15.7-dev:/nix/store/y13hxghkg99kng3d4wx80p6avxcs5a8b-qtwayland-5.15.7-dev:/nix/store/jqqbwn2vyf8lyryd9yhr716hb4s3vgll-qtdeclarative-5.15.7-dev:/nix/store/fxvcb3c5zxcq7bj5xd3ylq8yh6vc7ily-qtsvg-5.15.7-dev:/nix/store/36qyfhdxswdhz4gnnqpyxr0byzq64jvc-qtmultimedia-5.15.7-dev
qmake PREFIX=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2 NIX_OUTPUT_OUT=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2 NIX_OUTPUT_DEV=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2 NIX_OUTPUT_BIN=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2 NIX_OUTPUT_DOC=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2/share/doc/qt-5.15.7 NIX_OUTPUT_QML=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2/lib/qt-5.15.7/qml NIX_OUTPUT_PLUGIN=/nix/store/4qc37r70sgk9q0g30m5zvd5fpcr7m3yb-chatterino2/lib/qt-5.15.7/plugins CONFIG+=release
Usage: qmake [mode] [options] [files]

QMake has two modes, one mode for generating project files based on
some heuristics, and the other for generating makefiles. Normally you
shouldn't [...] <continues spitting out the qmake help text>

The overlay:

self: super:
{
	chatterino2 = super.chatterino2.overrideAttrs (oldAttrs: rec {
		version = "2.4.0";
		pname = "chatterino2";
		src = super.fetchFromGitHub {
			owner = "Chatterino";
			repo = pname;
			rev = "v${version}";
			sha256 = "sha256-6t7Or2heyV0B5zdWZpN80iADe52faNVlIEZYtcixpZo=";
			fetchSubmodules = true;
		};
	});
}

Anyone know what could be going on here?