For anyone who gets the following error:
./stardew_valley_1_4_3_379_34693.sh: line 509: ./startmojo.sh: Permission denied

You can patch the installer by simply telling it to use the local directory instead of /tmp:
echo y | dd of=./stardew_valley_1_4_3_379_34693.sh bs=1 seek=556 conv=notrunc

This is because the .sh file is a shell script with a binary archive appended to it. The script extracts the archive into /tmp, and then attempts to execute a secondary installer inside the archive. However for some, the /tmp directory is not executable for security reasons. So we simply change keep="n" to keep="y", and it extracts to the local directory instead of /tmp. Problem solved.

We have to use dd though, because using a text editor will corrupt the binary archive data at the end of the file because it contains invalid text characters. So I just used a hex editor to find what byte the "n" is stored in, and then we can write to only that byte.

Et voila, the installer works.

For anyone finding this post from google search: passing the --keep option to the installer also works and does not require editing the .sh file (although maybe it did not work with previous versions).

And yes, you are having this specific error because your /tmp is mounted with noexec. This is good. Friends don't let friends mount /tmp with exec.

Remember to remove the "binaries" folder that will get created next to the script after running it with --keep.

Sweetness Frenchy.

I get "Uncompressing <insert game> (GOG.com) 100% Extraction failed.", do you happen to know what causes that?

Thanks.