This script failed with Error None

I’m trying to install EndeavourOS on an old Imac Mid2011.
The user interface is really nice and smooth.
I try to use the online version of the installer and it was failing really at the beginning (due to dangling symlink). Now I try with the offline version and it goes much further.
Unfortunately not until the end.
Does someone knows what has to be done manually to finish the installation ? Like installing the EFI loader and that’s it ?

Thanks for your help

Here is the log:
08:34:43 [6]: Calamares::JobResult unmountTargetMounts(const QString&)
Read 7 entries from “/tmp/calamares-root-uh9z_3xz/”
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/sys/firmware/efi/efivars”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/sys”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/run/udev”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/run”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/proc”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/efi”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz/dev”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
… Running QList(“umount”, “-lv”, “/tmp/calamares-root-uh9z_3xz”)
… Running QList(“udevadm”, “settle”)
… Running QList(“sync”)
08:34:44 [1]: void Calamares::ViewManager::onInstallationFailed(const QString&, const QString&)
ERROR: Installation failed: “Failed to run script”
… - message: “Failed to run script”
… - details: The script failed with error None
08:34:44 [6]: void Calamares::ViewManager::onInstallationFailed(const QString&, const QString&)
Calamares will quit when the dialog closes.
08:34:44 [6]: DEBUG (Qt): QML Component (default slideshow) deactivated
08:34:44 [6]: void Config::doNotify(bool, bool)
Notification not sent; completion: failed
08:34:44 [6]: void {anonymous}::PowerManagementInterface::uninhibitSleep()
Sleep was never inhibited.
08:35:09 [6]: void Config::doRestart(bool)
mode= “never” user wants restart? false force restart? false
Shutting down Calamares…
Finished shutdown.

The actual error is above the point in the logs you quoted. We would need to see the entire log.

https://discovery.endeavouros.com/forum-log-tool-options/how-to-include-systemlogs-in-your-post/2021/03/

Without the full log hard to say for sure…