On julia 1.0, with PyCall#master I get
julia> using PyCall
julia> try
@pyimport pip
catch
println("failed")
end
ERROR: syntax: unsupported `const` declaration on local variable around /home/j/.julia/packages/PyCall/lhrke/src/PyCall.jl:526
julia> @pyimport pip
julia>
On julia 1.0, with PyCall#master I get