support build_wheel_for_editable

README.rst

@@ -73,11 +73,13 @@ Example enscons projects
 
 Right now, the best way to learn how enscons works is by example.
 
-* `rsalette <https://bitbucket.org/dholth/rsalette/src>`_ Simple package with just two modules.
-* `cryptacular <https://bitbucket.org/dholth/cryptacular/src>`_ Has a C extension.
-* `pysdl2-cffi <https://bitbucket.org/dholth/pysdl2-cffi/src>`_ Generates Python and C source code as part of the build, then compiles the generated source.
+* `rsalette <https://github.com/dholth/rsalette/>`_ Simple package with just two modules.
+* `cryptacular <https://github.com/dholth/cryptacular/>`_ Has a C extension.
+* `pysdl2-cffi <https://github.com/dholth/pysdl2-cffi/>`_ Generates Python and C source code as part of the build, then compiles the generated source.
 * `hello-pyrust <https://github.com/dholth/hello-pyrust>`_ An extension using `Rust <https://www.rust-lang.org/>`_ and `cffi <http://cffi.readthedocs.io/en/latest/>`_ instead of C.
-* `enscons <https://bitbucket.org/dholth/enscons/src>`_ Enscons builds itself.
+* `enscons <https://github.com/dholth/enscons/>`_ Enscons builds itself.
+* `nonstdlib <https://github.com/dholth/nonstdlib/>`_ Experimental repackaging of the Python standard library into many wheels.
+
 
 More about SCons
 ================

enscons/__init__.py

@@ -231,6 +231,25 @@ def urlsafe_b64encode(data):
     return base64.urlsafe_b64encode(data).rstrip(b"=")
 
 
+def add_editable(target, source, env):
+    """
+    Add the editable stub modules to a zip file.
+    """
+    import zipfile
+    import editables
+    import os.path
+
+    src_root = os.path.abspath(env["PACKAGE_METADATA"].get("src_root", ""))
+
+    archive = zipfile.ZipFile(
+        target[0].get_path(), "a", compression=zipfile.ZIP_DEFLATED
+    )
+    lines = []
+    for f, data in editables.build_editable(src_root):
+        archive.writestr(zipfile.ZipInfo(f, time.gmtime(SOURCE_EPOCH_ZIP)[:6]), data)
+    archive.close()
+
+
 def add_manifest(target, source, env):
     """
     Add the wheel manifest.
@@ -320,6 +339,24 @@ def init_wheel(env):
 
     targets = wheelmeta + wheel_entry_points
 
+    # experimental PEP517-style editable
+    # with filename that won't collide with our real wheel (SCons wouldn't like that)
+    editable_filename = (
+        "-".join(
+            (env["PACKAGE_NAME_SAFE"], env["PACKAGE_VERSION"], "ed." + env["WHEEL_TAG"])
+        )
+        + ".whl"
+    )
+    editable = env.Zip(
+        target=env.Dir(env["WHEEL_DIR"]).File(editable_filename),
+        source=env["DIST_INFO_PATH"],
+        ZIPROOT=env["WHEEL_PATH"],
+    )
+    env.Alias("editable", editable)
+    env.NoClean(editable)
+    env.AddPostAction(editable, Action(add_editable))
+    env.AddPostAction(editable, Action(add_manifest))
+
     return targets
 
 

enscons/api.py

@@ -49,3 +49,11 @@ def build_sdist(sdist_directory, settings):
         target_name = str(target)
         if target_name.endswith(".tar.gz"):
             return os.path.basename(target_name)
+
+
+# experimental PEP517-style editable installation
+def build_wheel_for_editable(
+    wheel_directory, scheme, settings, metadata_directory=None
+):
+    sys.argv[1:] = ["--wheel-dir=" + wheel_directory, "editable"]
+    return _run("editable")

pyproject.toml

@@ -1,12 +1,12 @@
 [build-system]
-requires = ["pytoml>=0.1", "scons", "enscons>=0.23"]
+requires = ["pytoml>=0.1", "scons", "enscons>=0.23", "editables"]
 build-backend = "enscons.api"
 
 [tool.enscons]
 name="enscons"
-version="0.23.0"
+version="0.24.0"
 packages=["enscons"]
-install_requires=["scons>=3.0.5", "pytoml>=0.1", "setuptools", "wheel", "attrs", "packaging"]
+install_requires=["scons>=3.0.5", "pytoml>=0.1", "setuptools", "wheel", "attrs", "packaging", "editables"]
 description="Tools for building Python packages with SCons"
 description_file="README.rst"
 license="MIT"
@@ -22,6 +22,7 @@ keywords=["packaging", "wheel"]
 author="Daniel Holth"
 author_email="dholth@fastmail.fm"
 url="https://bitbucket.org/dholth/enscons"
+src_root="."
 
 [tool.enscons.entry_points]
 console_scripts = ["setup2toml = enscons.setup2toml:main"]