After installing Ubuntu as a second system on my Macbook following this tutorial https://www.maketecheasier.com/install-dual-boot-ubuntu-mac/ everything was just working fine and I was able to boot into either macOS or Ubuntu via rEFInd.
Then I resized macOS's partition again to create a partition to share data between macOS and Ubuntu. Unfortunately rEFInd does not find the macOS Partition anymore and I am therefore not able to boot into macOS.
My partitions look like this at the moment:
sda 489,1G ├─sda1 vfat 200M /boot/efi EFI ├─sda2 apfs 351G ├─sda3 swap 3,7G [SWAP] ├─sda4 ext4 115,5G / └─sda5 vfat 18,6G SHARE
Any help would be highly appreciated.
I used the builtin Mac Program to resize the partition
sudo gdisk -l /dev/sda:
GPT fdisk (gdisk) version 1.0.5 Partition table scan: MBR: hybrid BSD: not present APM: not present GPT: present Found valid GPT with hybrid MBR; using GPT. Disk /dev/sda: 1025610768 sectors, 489.0 GiB Model: Crucial_CT525MX3 Sector size (logical/physical): 512/512 bytes Disk identifier (GUID): 2AA86904-096B-4D1C-9DD0-3C8B1FD84B37 Partition table holds up to 128 entries Main partition table begins at sector 2 and ends at sector 33 First usable sector is 34, last usable sector is 1025610734 Partitions will be aligned on 8-sector boundaries Total free space is 1653 sectors (826.5 KiB) Number Start (sector) End (sector) Size Code Name 1 40 409639 200.0 MiB EF00 EFI System Partition 2 409640 736548223 351.0 GiB FFFF tichan 3 775612416 783423487 3.7 GiB 8200 4 783423488 1025609727 115.5 GiB 8300 5 736548864 775612415 18.6 GiB 0700