Cannot use SymbolicControlSystems on Ubuntu 20.04

[ufechner7]

julia> using SymbolicControlSystems
[ Info: Precompiling SymbolicControlSystems [886cb795-8fd3-4b11-92f6-8071e46f71c5]
[ Info: Skipping precompilation since __precompile__(false). Importing SymbolicControlSystems [886cb795-8fd3-4b11-92f6-8071e46f71c5].
ERROR: LoadError: InitError: KeyError: key :pi not found
Stacktrace:
  [1] __getproperty
    @ ~/.julia/packages/PyCall/ilqDX/src/PyCall.jl:313 [inlined]
  [2] getproperty
    @ ~/.julia/packages/PyCall/ilqDX/src/PyCall.jl:318 [inlined]
  [3] __init__()
    @ SymPy ~/.julia/packages/SymPy/vpIrQ/src/SymPy.jl:131
  [4] register_restored_modules(sv::Core.SimpleVector, pkg::Base.PkgId, path::String)
    @ Base ./loading.jl:1115
  [5] _include_from_serialized(pkg::Base.PkgId, path::String, ocachepath::String, depmods::Vector{Any})
    @ Base ./loading.jl:1061
  [6] _require_search_from_serialized(pkg::Base.PkgId, sourcepath::String, build_id::UInt128)
    @ Base ./loading.jl:1506
  [7] _require(pkg::Base.PkgId, env::String)
    @ Base ./loading.jl:1783
  [8] _require_prelocked(uuidkey::Base.PkgId, env::String)
    @ Base ./loading.jl:1660
  [9] macro expansion
    @ ./loading.jl:1648 [inlined]
 [10] macro expansion
    @ ./lock.jl:267 [inlined]
 [11] require(into::Module, mod::Symbol)
    @ Base ./loading.jl:1611
 [12] include
    @ ./Base.jl:457 [inlined]
 [13] _require(pkg::Base.PkgId, env::String)
    @ Base ./loading.jl:1840
 [14] _require_prelocked(uuidkey::Base.PkgId, env::String)
    @ Base ./loading.jl:1660
 [15] macro expansion
    @ ./loading.jl:1648 [inlined]
 [16] macro expansion
    @ ./lock.jl:267 [inlined]
 [17] require(into::Module, mod::Symbol)
    @ Base ./loading.jl:1611
during initialization of module SymPy
in expression starting at /home/ufechner/.julia/packages/SymbolicControlSystems/wPScY/src/SymbolicControlSystems.jl:2

[baggepinnen]

That looks like a problem with your local configuration of SymPy, not with this package. The latest version of SymPy.jl works fine here

[ufechner7]

As I said before, SymPy.jl is evil. I know how to fix SymPy issues, but often it just doesn't work. Better use SymPyPythonCall.jl, much more reliable.

[ufechner7]

OK, I was finally able to fix this issue:

• I deleted the .julia folder
• installed sympy locally with pip install SymPy
• created a test project and added SymPy which worked
• then re-instantiated my main project

So I can use this package now, but only if I am not using my main project. So I will continue to work on my SyPyPythonCall based fork...