[ SOLVED ] Linux Mint 19.3 unable to compile latest Dev release

[KHg8m3r]

Linux Mint 19.3 is based on Ubuntu 18.04, and both of them use an older version of gcc/g++ that doesn't seem to play nicely with the external fmt library that Dolphin provides. Your two options are to upgrade to Linux Mint 20.3 (Ubuntu 20.04) or update your compiler on Linux Mint 19.3.

If you want to keep using Linux Mint 19.3, here's what I tested on Linux Mint 19.3 Cinnamon:

Spoiler: (Show Spoiler)

# Install gcc-9/g++-9:
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update && sudo apt upgrade
sudo apt install gcc-9 g++-9

# You can change your default gcc compiler to gcc-9 if you want by following this post (change 8 for 9):
https://askubuntu.com/a/1028656

# Confirm you have gcc-9 installed
gcc-9 -v
(if you changed the default) gcc -v

# Follow the build instructions for Dolphin on Linux
https://wiki.dolphin-emu.org/index.php?title=Building_Dolphin_on_Linux
(I had to run the `sudo apt install <packages> again cause I broke my Qt5 install messing around testing various things)

# If you still have your old git folder that's fine too, just delete the `build` folder you created and start fresh

# If you changed your default gcc to gcc-9, then just run through building as normal

# If you didn't change your default, you have to run cmake to point to gcc-9
cmake .. -DCMAKE_C_COMPILER=gcc-9 -DCMAKE_CXX_COMPILER=g++-9

# The first few lines of the cmake output will tell you if it's using gcc 9.4.0 or gcc 7.7.0

# Build Dolphin
make -j$(nproc)

# Create a bash script if you want that'll run through the make process for you. An example is on the Building Dolphin for Linux page