Get a notification when latexmk fails

latexc.py

#!/usr/bin/env python3

import subprocess
import sys

def main():
    proc = subprocess.Popen(['latexmk', '-pvc'] + sys.argv[1:],
                            stdin=subprocess.PIPE,
                            stdout=subprocess.PIPE,
                            stderr=subprocess.STDOUT,
                            bufsize=0,
                            universal_newlines=False)
    out = ''
    while True:
        li = proc.stdout.read(1)
        if not li:
            if proc.poll() is not None:
                sys.exit(1)
            continue
        li = li.decode('utf-8', 'ignore')
        out += li
        out = out[-2000:]
        if out.endswith('\n? '):
            # then we have failed, so log an error
            out = '\n'.join(out.split('\n')[-10:-1])
            print('send notification')
            subprocess.Popen(['notify-send', '-t', '10000', '-u', 'critical',
                              'Latex compile failed', out])
            # make it continue to compile
            if sys.argv[0].endswith('r'):
                proc.stdin.write(b'R\n')
            else:
                proc.stdin.write(b'X\n')
        sys.stdout.write(li)

if __name__ == '__main__':
    main()

On OSX use the following instead of notify-send

osascript -e 'display notification "Lorem ipsum dolor sit amet" with title "Title"'