Catch some edge-cases reported by JET

src/ambiguities.jl

@@ -64,7 +64,10 @@ normalize_exclude(::Any) = error("Only a function and type can be excluded.")
 function getobj((pkgid, name)::ExcludeSpec)
     nameparts = Symbol.(split(name, "."))
     m = Base.require(pkgid)
-    return foldl(getproperty, nameparts, init = m)
+    for name in nameparts
+        m = getproperty(m, name)
+    end
+    return m
 end
 
 function normalize_and_check_exclude(exclude::AbstractVector)
@@ -133,7 +136,14 @@ function _find_ambiguities(
             num_ambiguities = if succ
                 0
             else
-                parse(Int, match(r"(\d+) ambiguities found", strout).captures[1])
+                reg_match = match(r"(\d+) ambiguities found", strout)
+
+                reg_match === nothing && error(
+                    "Failed to parse output of `detect_ambiguities`. The output was:\n" *
+                    strout,
+                )
+
+                parse(Int, reg_match.captures[1])
             end
             return num_ambiguities, strout, strerr
         end
@@ -154,11 +164,11 @@ end
 
 function reprpkgid(pkg::PkgId)
     name = pkg.name
-    if pkg.uuid === nothing
+    uuid = pkg.uuid
+    if uuid === nothing
         return "Base.PkgId($(repr(name)))"
     end
-    uuid = pkg.uuid.value
-    return "Base.PkgId(Base.UUID($(repr(uuid))), $(repr(name)))"
+    return "Base.PkgId(Base.UUID($(repr(uuid.value))), $(repr(name)))"
 end
 
 struct _NoValue end

src/piracy.jl

@@ -104,7 +104,7 @@ function is_foreign(@nospecialize(T::DataType), pkg::Base.PkgId; treat_as_own)
         return is_foreign(first(params), pkg; treat_as_own = treat_as_own)
     else
         # Both the type itself and all of its parameters must be foreign
-        return !(C in treat_as_own) &&
+        return !((C in treat_as_own)::Bool) &&
                is_foreign_module(parentmodule(T), pkg) &&
                all(param -> is_foreign(param, pkg; treat_as_own = treat_as_own), params)
     end
@@ -153,8 +153,12 @@ function is_foreign_method(@nospecialize(T::DataType), pkg::Base.PkgId; treat_as
     end
 
     # fallback to general code
-    return !(T in treat_as_own) &&
-           !(T <: Function && isdefined(T, :instance) && T.instance in treat_as_own) &&
+    return !((T in treat_as_own)::Bool) &&
+           !(
+               T <: Function &&
+               isdefined(T, :instance) &&
+               (T.instance in treat_as_own)::Bool
+           ) &&
            is_foreign(T, pkg; treat_as_own = treat_as_own)
 end
 

src/project_extras.jl

@@ -33,7 +33,10 @@ function _analyze_project_extras(pkg::PkgId)
     result isa LazyTestResult && return result
     root_project_path = result
 
-    pkgpath = dirname(dirname(Base.locate_package(pkg)))
+    package_loc = Base.locate_package(pkg)
+    package_loc === nothing &&
+        return LazyTestResult(label, "Base.locate_package failed.", false)
+    pkgpath = dirname(dirname(package_loc))
     test_project_path, found = project_toml_path(joinpath(pkgpath, "test"))
     if !found
         return LazyTestResult(label, "test/Project.toml file does not exist.", true)