He escrito una aplicación de matraz y funciona perfectamente bien. Quería distribuirlo como un ejecutable. Intenté hacerlo usando la carpeta dist de pyinstaller flaskScript.py dist. Entré en la carpeta dist y hice doble clic en mi flaskScript ejecutable, se inicia mi servidor. Al acceder a la url, localhost: 9090 da la siguiente excepción

jinja2.exceptions.TemplateNotFound

TemplateNotFound: index.html

Traceback (most recent call last)
File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1836, in __call__

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1820, in wsgi_app

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1403, in handle_exception

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1817, in wsgi_app

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1477, in full_dispatch_request

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1381, in handle_user_exception

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1475, in full_dispatch_request

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.app", line 1461, in dispatch_request

File "<string>", line 13, in index

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.templating", line 127, in render_template

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/jinja2.environment", line 851, in get_or_select_template

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/jinja2.environment", line 812, in get_template

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/jinja2.environment", line 774, in _load_template

File "/Users/george/Downloads/flaskApps/flaskScript/build/flaskScript/out00-PYZ.pyz/flask.templating", line 64, in get_source

TemplateNotFound: index.html

Si bien funciona bien en la configuración del desarrollador al ejecutar python flaskScript.py