Make user confs have at leats one : separator

[AbrilRBS]

Changelog: Bugfix: Ensure user confs have at least 1 : separator
Changelog: Fix: Fix user confs package scoping when no separator was given
Docs: Omit

Fix comes from trying to fix error messages when they disdnt have a : but were scoped

[AbrilRBS]

Failing test, fixing it now

[memsharded]

Looking good, just a couple of details

[franramirez688]

@RubenRBS From my point of view, the changes to be made should be something like this:

diff --git a/conans/model/conf.py b/conans/model/conf.py
index 4a46d91ec..45f1d4000 100644
--- a/conans/model/conf.py
+++ b/conans/model/conf.py
@@ -116,9 +116,9 @@ BUILT_IN_CONFS = {
 BUILT_IN_CONFS = {key: value for key, value in sorted(BUILT_IN_CONFS.items())}


-CORE_CONF_PATTERN = re.compile(r"^core[.:]")
-TOOLS_CONF_PATTERN = re.compile(r"^tools[.:]")
-USER_CONF_PATTERN = re.compile(r"^user[.:]")
+CORE_CONF_PATTERN = re.compile(r"^(core\..+|core):.*")
+TOOLS_CONF_PATTERN = re.compile(r"^(tools\..+|tools):.*")
+USER_CONF_PATTERN = re.compile(r"^(user\..+|user):.*")


 def _is_profile_module(module_name):
@@ -496,8 +496,9 @@ class Conf:
     @staticmethod
     def _check_conf_name(conf):
         if USER_CONF_PATTERN.match(conf) is None and conf not in BUILT_IN_CONFS:
-            raise ConanException(f"[conf] '{conf}' does not exist in configuration list. "
-                                 f" Run 'conan config list' to see all the available confs.")
+            raise ConanException(f"[conf] Either '{conf}' does not exist in configuration list or "
+                                 f"the conf format introduced is not valid. Run 'conan config list' "
+                                 f"to see all the available confs.")

I think that this should cover everything 😁

UPDATED: I just updated the pattern 😅