Yuya Nishihara authored
In other words, RHEL6 is no longer supported. We need to switch our codebase to new-style signals to support PyQt5, but old PyQt versions are known to have bugs leading to crash. Supporting these versions would be a mess. https://bitbucket.org/tortoisehg/thg/wiki/developers/PyQtPitfalls9e7ba8f65ed0
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