Pinned packages listed in `conda_build_config.yaml` have their version number interpreted as floats when in format x.x and as strings when in format x.x.x when loaded by the pyyaml library in `bob.devtools/bob/devtools/build.py` in the `load_packages_from_conda_build_config` method. The problem is, for instance, that if we want the package `python-graphviz=0.20` conda will search for `python-graphviz=0.2` and may return an error as it doesn't find the package in this version. A solution could be to write all the package versions' numbers between quotes so they are all interpreted as strings.