That is strange - the tools are used every so often and is receiving ongoing maintenance.
I cannot say what your issue may be and the messages - disturbing as they look - have no consequence for the final ISO.
The most important output is the last lines of the console output - say about 20 lines or so.
I can do a proofreading of the wiki page - but that is about it - of course I can do a test run on my system.
Test run
07:57:58 ○ [fh@tiger] ~
$ buildiso -p xfce -n -k linux612 -b stable
--> Profile: [xfce]
==> Start building [xfce]
==> Cleaning up ...
-> Deleting chroot [rootfs] (x86_64) ...
-> Deleting isoroot [iso] ...
--> Loading Packages: [Packages-Root] ...
==> Prepare [Base installation] (rootfs)
--> mirror: https://mirror.easyname.at/manjaro/stable/$repo/$arch
==> Creating install root at /a/projects/builddir/root/buildiso/xfce/x86_64/rootfs
-> Installing packages to /a/projects/builddir/root/buildiso/xfce/x86_64/rootfs
[...]
==> Making bootable image
==> Creating ISO image...
xorriso 1.5.6 : RockRidge filesystem manipulator, libburnia project.
Drive current: -outdev 'stdio:/miso/iso/manjaro/xfce/25/manjaro-xfce-25-minimal-250330-linux612.iso'
Media current: stdio file, overwriteable
Media status : is blank
Media summary: 0 sessions, 0 data blocks, 0 data, 591g free
Added to ISO image: directory '/'='/a/projects/builddir/root/buildiso/xfce/iso'
xorriso : UPDATE : 820 files added in 1 seconds
xorriso : UPDATE : 820 files added in 1 seconds
xorriso : NOTE : Copying to System Area: 512 bytes from file '/a/projects/builddir/root/buildiso/xfce/iso/boot/grub/i386-pc/boot_hybrid.img'
libisofs: NOTE : Automatically adjusted MBR geometry to 1021/145/32
xorriso : UPDATE : 14.10% done
ISO image produced: 1185887 sectors
Written to medium : 1185887 sectors at LBA 0
Writing to 'stdio:/miso/iso/manjaro/xfce/25/manjaro-xfce-25-minimal-250330-linux612.iso' completed successfully.
==> Done [Build ISO]
--> Time compress_images: 2.17 minutes
==> Finished building [xfce]
--> Time make_profile: 4.72 minutes
possible gotcha
The most obvious problem may be the writing to USB. The command may exit early but the file system buffer data is still being flushed to USB. If the USB is removed before all data is flushed - your write will be incomplete and you get error trying to boot.
USB helper package
We have a new package in the repo - intended to adjust when the system reports back on write complete.
The package is udev-usb-sync available from all up-to-date mirrors.
iso boot tool
Another valuable tool is ventoy - also in the repo - which provides another method of booting using a regular .iso file stored on the USB.
sudo pacman -Syu udev-usb-sync ventoy
Then prepare an USB stick using the Ventoy2Disk GUI from your application launcher.
When prepared - drag your iso and drop it on the Ventoy partition of the preprared USB.
Boot the system and select your ISO - when selected you have two choices
- normal mode
- grub2 mode
Normal mode usually work - but sometimes it doesn’t - making grub2 mode the best choice for an iso build with our tools.