do not match generic invocations to their base body types

compiler/sigmatch.nim

@@ -1777,6 +1777,9 @@ proc typeRel(c: var TCandidate, f, aOrig: PType,
       result = isGeneric
     elif concpt.kind == tyConcept:
       result = enterConceptMatch(c, f, x, flags)
+    elif x.kind == tyGenericBody and f[0] == x:
+      # not specific enough
+      result = isNone
     else:
       let genericBody = f[0]
       var askip = skippedNone

testament/important_packages.nim

@@ -35,7 +35,9 @@ proc pkg(name: string; cmd = "nimble test -l"; url = "", useHead = true, allowFa
 
 pkg "alea"
 pkg "argparse"
-pkg "arraymancer", "nimble install -y; nimble uninstall -i -y nimcuda; nimble install [email protected]; nim c tests/tests_cpu.nim"
+pkg "arraymancer", "nimble install -y; nimble uninstall -i -y nimcuda; nimble install [email protected]; nim c tests/tests_cpu.nim",
+  # remove when https://github.com/mratsim/Arraymancer/pull/674 is merged
+  url = "https://github.com/metagn/Arraymancer"
 pkg "ast_pattern_matching", "nim c -r tests/test1.nim"
 pkg "asyncftpclient", "nimble compileExample"
 pkg "asyncthreadpool", "nimble test --mm:refc"

tests/generics/tgenerics_issues.nim

@@ -741,7 +741,8 @@ block t1684:
 block t5632:
   type Option[T] = object
 
-  proc point[A](v: A, t: typedesc[Option[A]]): Option[A] =
+  # original issue test uses Option[A] instead
+  proc point[A](v: A, t: typedesc[Option]): Option[A] =
     discard
 
   discard point(1, Option)

tests/overload/tgenericbodymatch.nim

@@ -0,0 +1,13 @@
+# issue #24688
+
+type
+  R[T, E] = object
+  A = object
+  B = object
+
+# Remove this overload to make it work
+func err[T](_: type R[T, void]): R[T, void] = discard
+
+func err(_: type R): R[A, B] = discard
+
+discard R.err()