It's been a while since I'd created a number dotnet projects and supporting solution using the command line so I had to refer to the documentation to keep me right. As I had just created a number of projects adding each one to the solution is a little tedious so when I'd spotted I could use globbing patterns I thought this would save time and a few key presses.
However, when I ran
dotnet sln Foo.sln add **/*.csproj I was presented with the error
Could not find project or directory **/*.csproj. It turns out that globbing is not actually supported by the CLI but actually a shell feature and PowerShell wasn't expanding the glob. Luckly as dotnet is cross platform and I have Windows Subsystem for Linux installed with all the dotnet goodness I could switch to
bash, ensure globbing was enabled using
shopt -s globstar, and then run
dotnet sln Foo.sln add **/*.csproj to add all my new projects, job done...