Debugging

Hydra provides a few options to improve debuggability.

Printing the configuration

Print the config for your app without running your function by adding --cfg or -c to the command line.

The --cfg option takes one argument indicating which part of the config to print:

• job : Your config
• hydra : Hydra's config
• all : The full config, which is a union of job and hydra.

# A normal run:
$ python my_app.py
MySQL connecting to localhost with user=root and password=1234

# just show the config without running your function:
$ python my_app.py --cfg job
db:
  host: localhost
  user: root
  password: 1234

The printed config includes any modifications done via the command line:

$ python my_app.py db.host=10.0.0.1 --cfg job
db:
  host: 10.0.0.1
  user: root
  password: 1234

You can use --package or -p to select a a specific config package:

python my_app.py --cfg hydra --package hydra.job
# @package hydra.job
name: my_app
config_name: config
...

Info

Hydra can print information about your plugins, config search path, composition trace and more using the
--info flag.

$ python my_app.py --info

Subset of output (Complete example)

Config search path
...
Profiling information
...
Composition trace
...
Config
...