I landed bug 1560977 a few days ago, so you can now see in a crash report if Fission was enabled. If it was, the "meta data" tab will have a value of 1 for DOMFissionEnabled. The behavior is modeled after DOMIPCEnabled which indicates when e10s is enabled. There is no explicit indicator if Fission is not enabled. The field isn't indexed or whatever yet, but I've filed bug 1563317 for that.
Here's an example of a crash report with DOMFissionEnabled: https://crash-stats.mozilla.org/report/index/dac0a91a-ad57-4446-9a82-505a80190705#tab-metadata _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform