"Unqualified lookup in templates" build failure(s)
clang 12.0.1
This code is accepted by g++. On purpose, clang 
does not accept this syntax.
// Uncomment this line will fix the issue.
// template<typename Value_t> void b(Value_t value)
template<typename Value_t> void a(Value_t value)
{
    b(value);
}
template<typename Value_t> void b(Value_t value)
{
}
void foo(int y)
{
    a(y);
}
| Package | Version | Supposed error message | Full log | Bug report | 
|---|
| anfo | 0.98-9 | stl_function.h:386:20: error: call to function 'operator<' that is neither visible in the template definition nor found by argument-dependent lookup | Log |  | 
             
| dbus-c++ | 0.9.0-8.2 | ../../include/dbus-c++/types.h:96:8: error: call to function 'operator>>' that is neither visible in the template definition nor found by argument-dependent lookup | Log |  | 
             
| dymo-cups-drivers | 1.4.0-11 | StringHelper.h:25:9: error: call to function 'operator<<' that is neither visible in the template definition nor found by argument-dependent lookup | Log |  | 
             
| libffado | 2.4.4-3 | types.h:566:9: error: call to function 'operator>>' that is neither visible in the template definition nor found by argument-dependent lookup | Log |  | 
             
| sane-backends | 1.0.32-4 | ./minigtest.h:43:29: error: call to function 'operator<<' that is neither visible in the template definition nor found by argument-dependent lookup | Log |  | 
             
| wreport | 3.23-2 | ../wreport/utils/tests.h:191:21: error: call to function 'operator<<' that is neither visible in the template definition nor found by argument-dependent lookup | Log |  | 
             
6 errors