[pve-devel] [RFC common] fix misleading warning caused by Devel::Cycle

[Thomas Lamprecht]

On 11/22/19 7:03 PM, Thomas Lamprecht wrote:
> On 11/22/19 6:21 PM, Stoiko Ivanov wrote:
>> When validating the parameters (or return values) of an API call against the
>> schema we run the parameter hash through Devel::Cycle::find_cycle.
>>
>> find_cycle has no handler for GLOB types (e.g. filehandles).
>> Recently we introduced passing a filehandle as return attribute in
>> PMG::API2::Quarantine::download
>>
>> When find_cycle encounters such an object it emits a warning:
>> `Unhandled type: GLOB at /usr/share/perl5/Devel/Cycle.pm line 109`
>> which ends up in the journal of pmgproxy (in that example).
>>
>> Since the line might mislead someone to think that this is a more serious bug
>> we silence it, by overriding the warnhandler ($SIG{'__WARN__'}, [0,1]) for the
>> time when find_cycle runs, to ignore messages starting with
>> 'Unhandled type: GLOB at'. The particular location of and in in Devel::Cycle
>> might change and is left out of the match.
>>
>> [0] man perlvar
>> [1] perldoc -f warn
>>
>> Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
>> ---
>>
>> sending as RFC, since the comment above the patch already indicate that we
>> could do away with the cycle-search on every call
> 
> I'd really rather to that, this is a build check, and thus we
> do not want to do it on every validation - besides those errors
> you ran into, it's also a bit costly..
> 
> I'd check for an environment variable, e.g. for "DEB_BUILD_ARCH",
> which we always have set when building. As some may want to have
> validation also in other cases we could also check a opt-in one,
> for example:
> 
> return if $ENV{DEB_BUILD_ARCH} && !$ENV{PROXMOX_FORCE_SCHEMA_VALIDATION};

argh, missed the ! from the $ENV{DEB_BUILD_ARCH}, could be written as

# only check when building a package or told to do so
return if !($ENV{DEB_BUILD_ARCH} || $ENV{PROXMOX_FORCE_SCHEMA_VALIDATION});