pygolang: Provide python-interpreter:exe

During my recent work I needed to use path for generated interpreter in
several places and found the need to repeat
${buildout:bin-directory}/${python-interpreter:interpreter} both tiring
and error-prone, because the knowledge where executable is placed
is implicitly used and relied upon.

On the other hand:

- pygolang already provides ${gpython:exe} as reference to the place
  where gpython is installed (see e1d269b4)

- pygolang already uses :exe for interpreter generated to accompany
  pyprog (see 0ee52376 and e328aa49)

So python-interpreter not providing :exe is an oversight and the logical
fix is to start providing python-interpreter:exe as well.

-> Do it and convert */software.cfg throughout the tree, where
python-interpreter is found, to use it.

/cc @jerome, @Tyagov, @alain.takoudjou, @xavier_thompson, @levin.zimmermann

component/pygolang/buildout.cfg

@@ -30,6 +30,8 @@ exe     = ${buildout:bin-directory}/gpython
 # python-interpreter provides python interpreter with all specified eggs.
 # eggs default to pygolang, but can be overwritten or changed in inherited section.
 # if eggs are changes, they must still have pygolang.
+#
+# ${python-interpreter:exe} is where buildout installs the interpreter.
 [python-interpreter]
 recipe = zc.recipe.egg:scripts
 eggs   = ${pygolang:egg}
@@ -47,6 +49,7 @@ initialization =
 # NOTE with scripts=ø interpreter is not handled, so we use `scripts=python` as
 # a workaround.
 scripts = ${:interpreter}
+exe     = ${buildout:bin-directory}/${:interpreter}
 
 
 # pyprog provides macro recipe to build python programs.
@@ -102,7 +105,6 @@ init =
   <= python-interpreter
   eggs += %(eggs)s
   interpreter = $${:_buildout_section_name_}
-  exe = $${buildout:bin-directory}/$${:interpreter}
   """ % locals())
 
 

software/beremiz-ide/software.cfg

@@ -113,7 +113,7 @@ url = ${:_profile_base_location_}/${:filename}
 recipe = slapos.recipe.template:jinja2
 output = ${buildout:directory}/instance.cfg
 url = ${:_profile_base_location_}/${:filename}
-python-bin = ${buildout:bin-directory}/${python-interpreter:interpreter}
+python-bin = ${python-interpreter:exe}
 type = beremiz
 context =
     key autoconf_location  autoconf:location

software/theia/software.cfg

@@ -138,7 +138,7 @@ needs-these-eggs-scripts-in-path =
 [python-for-buildout-languageserver]
 <= python-interpreter
 interpreter = ${:_buildout_section_name_}
-executable = ${buildout:bin-directory}/${:interpreter}
+executable = ${:exe}
 eggs +=
   zc.buildout.languageserver
 

stack/erp5-zope2/buildout.cfg

@@ -230,7 +230,7 @@ context =
     key unixodbc_location unixodbc:location
     key wget_location wget:location
     key extra_path_list eggs:extra-paths
-    key python_executable_for_kernel erp5-python-interpreter-jupyter:interpreter_path
+    key python_executable_for_kernel erp5-python-interpreter-jupyter:exe
     key erp5_kernel_location erp5-kernel:location
     key erp5_kernel_filename erp5-kernel:filename
     key kernel_json_location kernel-json:location
@@ -493,7 +493,6 @@ extra-paths += ${eggs:extra-paths}
 [erp5-python-interpreter-jupyter]
 <= erp5-python-interpreter
 interpreter = pythonwitheggs_jupyter
-interpreter_path = ${buildout:directory}/bin/${:interpreter}
 eggs +=
   jupyter_client
   jupyter_core

stack/erp5/buildout.cfg

@@ -232,7 +232,7 @@ context =
     key unixodbc_location unixodbc:location
     key wget_location wget:location
     key extra_path_list eggs:extra-paths
-    key python_executable_for_kernel erp5-python-interpreter-jupyter:interpreter_path
+    key python_executable_for_kernel erp5-python-interpreter-jupyter:exe
     key erp5_kernel_location erp5-kernel:location
     key erp5_kernel_filename erp5-kernel:filename
     key kernel_json_location kernel-json:location
@@ -495,7 +495,6 @@ extra-paths += ${eggs:extra-paths}
 [erp5-python-interpreter-jupyter]
 <= erp5-python-interpreter
 interpreter = pythonwitheggs_jupyter
-interpreter_path = ${buildout:directory}/bin/${:interpreter}
 eggs +=
   jupyter_client
   jupyter_core