Since the dependency is pointing to a branch SPM can not resolve it:
Computing version for https://github.com/PureSwift/BluetoothLinux
error: Dependencies could not be resolved because root depends on 'bluetoothlinux' 5.0.5..<5.1.0.
'bluetoothlinux' >= 5.0.5 cannot be used because no versions of 'bluetoothlinux' match the requirement 5.0.6..<5.1.0 and package 'bluetoothlinux' is required using a stable-version but 'bluetoothlinux' depends on an unstable-version package 'socket'.
The package file of a tagged version should point to a dependency with a tagged version.
In the Package.swift ,of the tagged version 5.0.5, is declared this dependency.
Since the dependency is pointing to a branch SPM can not resolve it:
The package file of a tagged version should point to a dependency with a tagged version.