I don't yet have a good explanation for what you report. It's confirmed by the fact that not all this bug's crashes have long uptimes. When you quit a process that leaks "resources", the kernel counterparts of those "resources" might not get freed right away. This could explain one long uptime followed by one or more short uptimes. That seems to be the pattern with your crashes, or at least one of the patterns.
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I don't yet have a good explanation for what you report. It's confirmed by the fact that not all this bug's crashes have long uptimes. When a process crashes that used lots of "resources", the kernel counterparts of those "resources" might not get freed right away. This could explain one long uptime followed by one or more short uptimes. That seems to be the pattern with your crashes, or at least one of the patterns.