using Pkg
Pkg.add(PackageSpec(url="https://github.com/MagneticParticleImaging/OpenMPIData.jl.git"))
yields
could not find project file in package at https://github.com/MagneticParticleImaging/OpenMPIData.jl.git
Stacktrace:
[1] pkgerror(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/Types.jl:53
[2] resolve_projectfile!(::Pkg.Types.Context, ::Pkg.Types.PackageSpec, ::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/Types.jl:629
[3] (::Pkg.Types.var"#54#55"{Pkg.Types.Context,Pkg.Types.PackageSpec})(::LibGit2.GitRepo) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/Types.jl:602
[4] with(::Pkg.Types.var"#54#55"{Pkg.Types.Context,Pkg.Types.PackageSpec}, ::LibGit2.GitRepo) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/LibGit2/src/types.jl:1125
[5] handle_repo_add!(::Pkg.Types.Context, ::Pkg.Types.PackageSpec) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/Types.jl:562
[6] handle_repos_add!(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/Types.jl:620
[7] add(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}; preserve::Pkg.Types.PreserveLevel, platform::Pkg.BinaryPlatforms.Linux, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/API.jl:139
[8] add(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/API.jl:112
[9] #add#27 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/API.jl:109 [inlined]
[10] add at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/API.jl:109 [inlined]
[11] #add#23 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/API.jl:106 [inlined]
[12] add(::Pkg.Types.PackageSpec) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/Pkg/src/API.jl:106
[13] top-level scope at In[8]:2
yields