anchor.diff:  The profile above can be saved to a file, for example `my-profile.yml`, and
   a virtual environment can be created out of it:
   
  -    vlttng -p my-profile.yml virt
  +----
  +vlttng -p my-profile.yml virt
  +----
   
   When multiple profiles are given to `vlttng`, the first profile is "patched"
   with the second, which is then patched with the third, and so on. Nonexistent
  
positive.code: 
  Replace a property::
  +
      PATH=REPLACEMENT
  
  
  Append to a property::
  +
      PATH+=APPEND
  
  Remove a property::
  +
      !PATH
  
  `PATH` is the path to the property, from the root of the profile, using
  a dot-separated list of keys.
  
  Example:
  
      -o projects.lttng-tools.configure+=--disable-bin-lttng-relayd \
      -o '!projects.lttng-ust.checkout' \
      -o build-env.CC=clang
  
  In replace and append modes, the property is created if it does not
  exist. This allows you to create projects on the command-line:
  
      -o projects.lttng-tools.source=https://github.com/lttng/lttng-tools.git \
      -o projects.lttng-tools.checkout=v2.7.1 \
      -o projects.lttng-tools.configure='--disable-bin-lttng --disable-man-pages'
  
  Note that the overrides are applied in command line order.
  
  
negative.code: 
  With this command:
  
  ----
  vlttng -p my-profile.yml -p more.yaml virt
  ----
  
  the effective profile is:
  
  