{"action":"created","issue":{"url":"https://api.github.com/repos/souffle-lang/souffle/issues/656","repository_url":"https://api.github.com/repos/souffle-lang/souffle","labels_url":"https://api.github.com/repos/souffle-lang/souffle/issues/656/labels{/name}","comments_url":"https://api.github.com/repos/souffle-lang/souffle/issues/656/comments","events_url":"https://api.github.com/repos/souffle-lang/souffle/issues/656/events","html_url":"https://github.com/souffle-lang/souffle/issues/656","id":321435976,"number":656,"title":"ReplaceSingletonVariables transformer causes segmentation fault","user":{"login":"anantoni","id":4331337,"avatar_url":"https://avatars2.githubusercontent.com/u/4331337?v=4","gravatar_id":"","url":"https://api.github.com/users/anantoni","html_url":"https://github.com/anantoni","followers_url":"https://api.github.com/users/anantoni/followers","following_url":"https://api.github.com/users/anantoni/following{/other_user}","gists_url":"https://api.github.com/users/anantoni/gists{/gist_id}","starred_url":"https://api.github.com/users/anantoni/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/anantoni/subscriptions","organizations_url":"https://api.github.com/users/anantoni/orgs","repos_url":"https://api.github.com/users/anantoni/repos","events_url":"https://api.github.com/users/anantoni/events{/privacy}","received_events_url":"https://api.github.com/users/anantoni/received_events","type":"User","site_admin":false},"labels":[{"id":340292149,"url":"https://api.github.com/repos/souffle-lang/souffle/labels/bug","name":"bug","color":"fc2929","default":true}],"state":"open","locked":false,"assignee":{"login":"azreika","id":18253832,"avatar_url":"https://avatars2.githubusercontent.com/u/18253832?v=4","gravatar_id":"","url":"https://api.github.com/users/azreika","html_url":"https://github.com/azreika","followers_url":"https://api.github.com/users/azreika/followers","following_url":"https://api.github.com/users/azreika/following{/other_user}","gists_url":"https://api.github.com/users/azreika/gists{/gist_id}","starred_url":"https://api.github.com/users/azreika/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/azreika/subscriptions","organizations_url":"https://api.github.com/users/azreika/orgs","repos_url":"https://api.github.com/users/azreika/repos","events_url":"https://api.github.com/users/azreika/events{/privacy}","received_events_url":"https://api.github.com/users/azreika/received_events","type":"User","site_admin":false},"assignees":[{"login":"azreika","id":18253832,"avatar_url":"https://avatars2.githubusercontent.com/u/18253832?v=4","gravatar_id":"","url":"https://api.github.com/users/azreika","html_url":"https://github.com/azreika","followers_url":"https://api.github.com/users/azreika/followers","following_url":"https://api.github.com/users/azreika/following{/other_user}","gists_url":"https://api.github.com/users/azreika/gists{/gist_id}","starred_url":"https://api.github.com/users/azreika/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/azreika/subscriptions","organizations_url":"https://api.github.com/users/azreika/orgs","repos_url":"https://api.github.com/users/azreika/repos","events_url":"https://api.github.com/users/azreika/events{/privacy}","received_events_url":"https://api.github.com/users/azreika/received_events","type":"User","site_admin":false}],"milestone":null,"comments":1,"created_at":"2018-05-09T05:31:33Z","updated_at":"2018-05-14T07:04:38Z","closed_at":null,"author_association":"CONTRIBUTOR","body":"Hello,\r\n\r\nI've been encountering a segmentation fault in the latest commits and I've managed to track down the commit that introduced the issue. Its hash is 1a2b08b8fb2f978969556c5868b2b5ed8c4dce16 and it adds the replace singleton variables transformer to pipeline so I expect the issue to be related to the replacement of singleton variables.\r\n\r\nBest regards,\r\nTony\r\n\r\nThis is the datalog file that causes the segmentation fault and the command is souffle -c: [context-insensitive.txt](https://github.com/souffle-lang/souffle/files/1986492/context-insensitive.txt)\r\n"},"comment":{"url":"https://api.github.com/repos/souffle-lang/souffle/issues/comments/388716882","html_url":"https://github.com/souffle-lang/souffle/issues/656#issuecomment-388716882","issue_url":"https://api.github.com/repos/souffle-lang/souffle/issues/656","id":388716882,"user":{"login":"azreika","id":18253832,"avatar_url":"https://avatars2.githubusercontent.com/u/18253832?v=4","gravatar_id":"","url":"https://api.github.com/users/azreika","html_url":"https://github.com/azreika","followers_url":"https://api.github.com/users/azreika/followers","following_url":"https://api.github.com/users/azreika/following{/other_user}","gists_url":"https://api.github.com/users/azreika/gists{/gist_id}","starred_url":"https://api.github.com/users/azreika/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/azreika/subscriptions","organizations_url":"https://api.github.com/users/azreika/orgs","repos_url":"https://api.github.com/users/azreika/repos","events_url":"https://api.github.com/users/azreika/events{/privacy}","received_events_url":"https://api.github.com/users/azreika/received_events","type":"User","site_admin":false},"created_at":"2018-05-14T07:04:38Z","updated_at":"2018-05-14T07:04:38Z","author_association":"COLLABORATOR","body":"Segfault seems to happen when trying to resolve an equality constraint in the RAM with an undefined left-hand side. I assume this has something to do with either alias resolution or a missing check for variable use in the transformer. Moving the transformer to occur after alias resolution (the `ResolveAliasesTransformer` transformation)  seems to solve the problem for this case, but I'm going to try for a minimal example to confirm before pulling changes up."}}
{"actor":{"display_login":"azreika"}}