I found that deleted post over on reddit with an answer from delipity. But the user continued to have problems. I unzipped a fresh pset7, and did these chmods and finally got RockRolld! (oops. Spoiler :). I then removed pset7 and reinstalled, then followed this list and got the same (positive) result. I am running IDE 62. Full disclosure, I did not reinstall the database.
~/workspace/ $ chmod 711 pset7 ~/workspace/ $ cd pset7 ~/workspace/pset7/ $ ls config.json includes/ public/ vendor/ views/ ~/workspace/pset7/ $ chmod 755 public ~/workspace/pset7/ $ cd public ~/workspace/pset7/public/ $ chmod 711 css fonts img js ~/workspace/pset7/public/ $ chmod 644 css/* fonts/* img/* js/* ~/workspace/pset7/public/ $ cd .. ~/workspace/pset7/ $ chmod 711 includes vendor views ~/workspace/pset7/ $ chmod 644 includes/* vendor/* views/* ~/workspace/pset7/ $ chmod 644 public/*php ~/workspace/pset7/ $ chmod 644 config.json ~/workspace/pset7/ $ cd vendor ~/workspace/pset7/vendor/ $ ls library50-php-5/ ~/workspace/pset7/vendor/ $ chmod 711 library50* ~/workspace/pset7/vendor/ $ cd library50* ~/workspace/pset7/vendor/library50-php-5/ $ ls CS50/ ~/workspace/pset7/vendor/library50-php-5/ $ chmod 711 CS50 ~/workspace/pset7/vendor/library50-php-5/ $ chmod 644 CS50/**php
EDIT The last line has been corrected from chmod 644 CS50/* to chmod 644 CS50/*php. This was not detected in running the (vanilla) app. If you already did the incorrect chmod, the correction is
cd ~/workspace/pset7/vendor/library50-php-5/ $chmod 711 CS50/share