fix setuptools-scm in docker

- needs git, .git files
- needs setuptools_scm config section in pyproject.toml

.dockerignore

@@ -5,6 +5,5 @@ jupyterhub.sqlite
 jupyterhub_config.py
 node_modules
 docs
-.git
 dist
 build

Dockerfile

@@ -44,6 +44,7 @@ RUN apt-get update -qq \
     build-essential \
     ca-certificates \
     curl \
+    git \
     locales \
     python3-dev \
     python3-pip \

pyproject.toml

@@ -91,6 +91,12 @@ include = ["jupyterhub*"]
 readme = { file = "README.md", content-type = "text/markdown" }
 dependencies = { file = "requirements.txt" }
 
+# setuptools_scm needs a section to be present
+[tool.setuptools_scm]
+# we don't actually use setuptools_scm for versions,
+# only the file-finder
+fallback_version = "0.0.0"
+
 # declarative data-files doesn't quite work right
 # this is still in setup.py:get_data_files
 # [tool.setuptools.data-files]