Choose shebang rewriting for pyproject scripts to match shebang target

Remember that linux has a very small (127) character shebang limit
and /usr/bin/env should be used all the time except for cases
where SIP is involved on macOS.

Author: timj

python/lsst/sconsUtils/builders.py

@@ -15,7 +15,7 @@
 
 from . import state
 from .installation import determineVersion, getFingerprint
-from .utils import memberOf, whichPython
+from .utils import memberOf, needShebangRewrite, whichPython
 
 
 @memberOf(SConsEnvironment)
@@ -805,11 +805,17 @@ def makePythonScript(target, source, env):
             return
         os.makedirs(os.path.dirname(cmdfile), exist_ok=True)
         package, func = scripts[command].split(":", maxsplit=1)
+        python_exe = whichPython()
+        if needShebangRewrite():
+            shebang = python_exe
+        else:
+            # Linux has very small shebang limit so always use env.
+            shebang = f"/usr/bin/env {os.path.basename(python_exe)}"
         with open(cmdfile, "w") as fd:
             # Follow setuptools convention and always change the shebang.
             # Can not add noqa on Linux for long paths so do not add anywhere.
             print(
-                rf"""#!{whichPython()}
+                rf"""#!{shebang}
 import sys
 from {package} import {func}
 if __name__ == '__main__':