Relevant successful helper execs and registration write opens.
Linux x86_64, packaged Electron, isolated XDG directories, generic backend.
Private paths, environment addresses and thread IDs normalized; no other trace rows included.

Launch 1: initial launch
77829 04:11:50.742670 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 43
77829 04:11:51.263049 rename("$XDG_CONFIG_HOME/mimeapps.list.GJHRY3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
78266 04:11:54.679101 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment>) = 0
78293 04:11:55.137423 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment>) = 0
78293 04:11:55.156820 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 9
78298 04:11:55.402648 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE) = -1 EEXIST (File exists)
78298 04:11:55.403327 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list") = 0
79685 04:12:22.690951 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 2: unchanged relaunch
80165 04:12:34.508288 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 42
80165 04:12:34.698170 rename("$XDG_CONFIG_HOME/mimeapps.list.Y1NTY3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
80478 04:12:37.685490 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment> ) = 0
80504 04:12:37.907603 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
80504 04:12:37.957103 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666 ) = 9
80523 04:12:38.038776 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE) = -1 EEXIST (File exists)
80523 04:12:38.039004 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list") = 0
81979 04:12:54.236242 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 3: missing MIME cache
82532 04:13:07.869488 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 43
82532 04:13:08.168118 rename("$XDG_CONFIG_HOME/mimeapps.list.VX5IY3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
82823 04:13:10.080511 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment> ) = 0
82843 04:13:10.172279 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
82843 04:13:10.180280 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 9
82849 04:13:10.232886 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE) = -1 EEXIST (File exists)
82849 04:13:10.233934 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list") = 0
83660 04:13:21.784553 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 4: stale MIME cache
84211 04:13:34.998442 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 43
84211 04:13:35.191406 rename("$XDG_CONFIG_HOME/mimeapps.list.DL1HY3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
84472 04:13:37.054863 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment>) = 0
84564 04:13:38.486058 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
84564 04:13:38.541478 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666 ) = 9
84575 04:13:38.563938 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE ) = -1 EEXIST (File exists)
84575 04:13:38.564173 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list" ) = 0
85736 04:13:45.022604 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 5: changed desktop entry
86162 04:13:54.642546 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 43
86162 04:13:54.800962 rename("$XDG_CONFIG_HOME/mimeapps.list.1RJ2Y3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
86384 04:13:56.906955 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment> ) = 0
86417 04:13:57.167470 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
86417 04:13:57.238309 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 9
86424 04:13:57.268972 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE) = -1 EEXIST (File exists)
86424 04:13:57.269284 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list") = 0
87359 04:14:05.495937 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 6: changed default
87837 04:14:16.851771 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 42
87837 04:14:16.926405 rename("$XDG_CONFIG_HOME/mimeapps.list.LEVZY3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
88208 04:14:20.569915 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment> ) = 0
88292 04:14:23.133017 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
88292 04:14:23.158501 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 9
88297 04:14:23.190158 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE ) = -1 EEXIST (File exists)
88297 04:14:23.190365 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list" ) = 0
88880 04:14:29.368462 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 7: damaged persistent icon
89407 04:14:43.703466 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 36
89407 04:14:43.906651 rename("$XDG_CONFIG_HOME/mimeapps.list.4NI0Y3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
90044 04:14:46.735412 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment>) = 0
90045 04:14:46.895001 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
90045 04:14:46.949812 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 9
90051 04:14:47.036046 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE) = -1 EEXIST (File exists)
90051 04:14:47.038433 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list") = 0
91075 04:15:02.968834 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0

Launch 8: unchanged after repair
91556 04:15:13.708364 openat(AT_FDCWD, "$XDG_DATA_HOME/applications/com.t3tools.T3Code.desktop", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 41
91556 04:15:13.858900 rename("$XDG_CONFIG_HOME/mimeapps.list.0UE1Y3", "$XDG_CONFIG_HOME/mimeapps.list") = 0
91958 04:15:15.929960 execve("/usr/bin/update-desktop-database", ["update-desktop-database", "$XDG_DATA_HOME/applications"], <environment>) = 0
91970 04:15:16.028614 execve("/usr/bin/xdg-mime", ["xdg-mime", "default", "com.t3tools.T3Code.desktop", "x-scheme-handler/t3code"], <environment> ) = 0
91970 04:15:16.063988 openat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 9
91975 04:15:16.112040 renameat2(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list", RENAME_NOREPLACE ) = -1 EEXIST (File exists)
91975 04:15:16.112544 renameat(AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list.new", AT_FDCWD, "$XDG_CONFIG_HOME/mimeapps.list" ) = 0
92752 04:15:29.751860 execve("/usr/bin/xdg-mime", ["xdg-mime", "query", "default", "inode/directory"], <environment> ) = 0