/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/ is in supercollider-common 1:3.4.5-1wheezy1.
This file is owned by root:root, with mode 0o755.
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/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/AudioHelpers.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/Constraint.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/Def.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/KeyCodeResponder.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/KeyCodeResponderGui.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/ModalFreqUGen.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/MultiChannelRecorder.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/PlayPathButton.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/PrettyPrintStream.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/UnicodeResponder.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/ZArchive.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/viewExtensions.sc
/usr/share/SuperCollider/SCClassLibrary/crucial/UncoupledUsefulThings/zArchiveSupport.sc