Fix juliainfo for the case when PyCall.jl is not installed

Author: tkf

julia/core.py

@@ -267,7 +267,12 @@ def determine_if_statically_linked():
      'pyprogramname', 'libpython'])
 
 
-def juliainfo(runtime='julia'):
+def juliainfo(runtime='julia', **popen_kwargs):
+    # Use the original environment variables to avoid a cryptic
+    # error "fake-julia/../lib/julia/sys.so: cannot open shared
+    # object file: No such file or directory":
+    popen_kwargs.setdefault("env", _enviorn)
+
     output = subprocess.check_output(
         [runtime, "-e",
          """
@@ -282,18 +287,19 @@ def juliainfo(runtime='julia'):
              PyCall_depsfile = Pkg.dir("PyCall","deps","deps.jl")
          else
              modpath = Base.locate_package(Base.identify_package("PyCall"))
-             PyCall_depsfile = joinpath(dirname(modpath),"..","deps","deps.jl")
+             if modpath == nothing
+                 PyCall_depsfile = nothing
+             else
+                 PyCall_depsfile = joinpath(dirname(modpath),"..","deps","deps.jl")
+             end
          end
          if PyCall_depsfile !== nothing && isfile(PyCall_depsfile)
              include(PyCall_depsfile)
              println(pyprogramname)
              println(libpython)
          end
          """],
-        # Use the original environment variables to avoid a cryptic
-        # error "fake-julia/../lib/julia/sys.so: cannot open shared
-        # object file: No such file or directory":
-        env=_enviorn)
+        **popen_kwargs)
     args = output.decode("utf-8").rstrip().split("\n")
     args.extend([None] * (len(JuliaInfo._fields) - len(args)))
     return JuliaInfo(*args)

test/test_juliainfo.py

@@ -0,0 +1,42 @@
+import os
+import subprocess
+
+from julia.core import juliainfo, _enviorn
+
+
+def check_core_juliainfo(jlinfo):
+    assert os.path.exists(jlinfo.JULIA_HOME)
+    assert os.path.exists(jlinfo.libjulia_path)
+    assert os.path.exists(jlinfo.image_file)
+
+
+def test_juliainfo_normal():
+    jlinfo = juliainfo(os.getenv("JULIA_EXE", "julia"))
+    check_core_juliainfo(jlinfo)
+    assert os.path.exists(jlinfo.pyprogramname)
+    # Note: jlinfo.libpython is probably not a full path so we are not
+    # testing it here.
+
+
+def test_juliainfo_without_pycall(tmpdir):
+    """
+    `juliainfo` should not fail even when PyCall.jl is not installed.
+    """
+
+    runtime = os.getenv("JULIA_EXE", "julia")
+
+    JULIA_DEPOT_PATH = subprocess.check_output(
+        [runtime, "-e", """
+        paths = [ARGS[1], DEPOT_PATH[2:end]...]
+        print(join(paths, Sys.iswindows() ? ';' : ':'))
+        """, str(tmpdir)],
+        env=_enviorn,
+        universal_newlines=True)
+
+    jlinfo = juliainfo(
+        runtime,
+        env=dict(_enviorn, JULIA_DEPOT_PATH=JULIA_DEPOT_PATH))
+
+    check_core_juliainfo(jlinfo)
+    assert jlinfo.pyprogramname is None
+    assert jlinfo.libpython is None