Unitful + Latexify extension won't work on old Julia anyway

Author: Ickaser

test/test_unitful.jl

@@ -294,12 +294,14 @@ end
         @test plot(y, label = P"meters") isa Plots.Plot
     end
 
-    @testset "latexify as unitformat" begin
-        y = rand(10) * u"m^-1"
-        @test yguide(plot(y, ylabel = "hello", unitformat = latexify)) == "\$hello\\;\\left/\\;\\mathrm{m}^{-1}\\right.\$"
+    if isdefined(Base, :get_extension)
+        @testset "latexify as unitformat" begin
+            y = rand(10) * u"m^-1"
+            @test yguide(plot(y, ylabel = "hello", unitformat = latexify)) == "\$hello\\;\\left/\\;\\mathrm{m}^{-1}\\right.\$"
 
-        uf = (l, u) -> l * " (" * latexify(u) * ")"
-        @test yguide(plot(y, ylabel = "hello", unitformat = uf)) == "hello (\$\\mathrm{m}^{-1}\$)"
+            uf = (l, u) -> l * " (" * latexify(u) * ")"
+            @test yguide(plot(y, ylabel = "hello", unitformat = uf)) == "hello (\$\\mathrm{m}^{-1}\$)"
+        end
     end
 
     @testset "colorbar title" begin