DevTools expects `inIDOMUtils.parseStyleSheet` to succeed, but currently it throws an error with Stylo. This breaks tests like devtools/client/inspector/rules/test/browser_rules_add-rule-then-property-edit-selector.js[1]. Message: [Exception... "Component returned failure code: 0x80070057 (NS_ERROR_ILLEGAL_VALUE) [inIDOMUtils.parseStyleSheet]" nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)" location: "JS frame :: resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js :: update :: line 733" data: no] Stack: update@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js:733:5 PageStyleActor<.addNewRule<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/styles.js:920:13 _run@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:311:39 process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:922:23 walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:806:7 Promise*scheduleWalkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:739:11 schedulePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:770:7 Promise.prototype.then@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:455:5 getText@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js:408:12 PageStyleActor<.addNewRule<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/styles.js:918:39 _run@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:311:39 TaskImpl@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:273:3 asyncFunction@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:247:14 handler@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/protocol.js:1082:19 onPacket@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/main.js:1760:15 receiveMessage@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/transport/transport.js:761:7 update@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js:733:5 PageStyleActor<.addNewRule<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/styles.js:920:13 _run@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:311:39 process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:922:23 walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:806:7 Promise*scheduleWalkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:739:11 schedulePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:770:7 Promise.prototype.then@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:455:5 getText@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js:408:12 PageStyleActor<.addNewRule<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/styles.js:918:39 _run@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:311:39 TaskImpl@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:273:3 asyncFunction@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/task.js:247:14 handler@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/protocol.js:1082:19 onPacket@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/main.js:1760:15 receiveMessage@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/transport/transport.js:761:7 [1]: https://treeherder.mozilla.org/logviewer.html#?job_id=101423388&repo=try&lineNumber=6735

Hi jryans, I'm working on Bug 1358993. I'll add ReparseSheet function for ServoStyleSheet and make it be called in inIDOMUtils.parseStyleSheet. Maybe this issue will be fixed when I finished.

(In reply to Tommy Kuo [:kuoe0] at UTC+8 from comment #1) > Hi jryans, I'm working on Bug 1358993. I'll add ReparseSheet function for > ServoStyleSheet and make it be called in inIDOMUtils.parseStyleSheet. Maybe > this issue will be fixed when I finished. Okay great! I'll track it as a dependency. :)

Seems like this is indeed fixed by bug 1358993, thanks :kuoe0!