group.of.nepali.translators team mailing list archive

[Louis Bouchard <louis.bouchard@xxxxxxxxxxxxx>]

Julian,

first of all, you are right, I did mix up the series, I'll fix that.

Now, Michael Vogt (mvo), Debian's APT main developer is currently
reviewing the one line fix that solves this issue.

I have a reproducer and was able to identify the root cause and prepare
a fix.

The source of the problem is the following :

    string msg = "\nIndex-File: true";
    // FIXME: this really should use "IndexTarget::IsOptional()" but that
    //        seems to be difficult without breaking ABI
    if (ShortDesc().find("Translation") != 0)

As outlined in the FIXME, IndexTarget::IsOptional() should be used, and
that is what started to happen with Wily. The code now reads :

   if(Target.IsOptional)
      msg += "\nFail-Ignore: true";

Here is the complete explanation as provided to MVO :

"When the Queue responsible for fetching the Package file runs, it builds the
Custom600 header with the following method :

> // AcqIndex::Custom600Headers - Insert custom request headers           /*{{{*/                                    
> // ---------------------------------------------------------------------                                           
> /* The only header we use is the last-modified header. */                                                          
> string pkgAcqIndex::Custom600Headers()                                                                             
> {                                                                                                                  
>    string Final = _config->FindDir("Dir::State::lists");                                                           
>    Final += URItoFileName(RealURI);                                                                                
>    if (_config->FindB("Acquire::GzipIndexes",false))                                                               
>       Final += ".gz";                                                                                              
>                                                                                                                    
>    string msg = "\nIndex-File: true";                                                                              
>    // FIXME: this really should use "IndexTarget::IsOptional()" but that                                           
>    //        seems to be difficult without breaking ABI                                                            
>    if (ShortDesc().find("Translation") != 0)                                                            
>       msg += "\nFail-Ignore: true";                                                                                
>    struct stat Buf;                                                                                                
>    if (stat(Final.c_str(),&Buf) == 0)                                                                              
>       msg += "\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);                                                      
>                                                                                                                    
>    return msg;                                                                                                     

The custom header is set with "Fail-Ignore: true" in the case of a Translation
file. This was true until Wily when the code got refactored to use
"IndexTarget::IsOptional" as mentionned in the FIXME.

As far as I can tell, the issue here is that this is wrong :

        if (ShortDesc().find("Translation") != 0)

when string::find() does not find the string, it returns string::npos so this
test is always true. This means that when Packages is downloaded, Fail-Ignore:
is also set to true, which means that TryNextMirror() will not retry.

In MirrorMethod::Failed() :

>    if (!Queue->FailIgnore && TryNextMirror())                                                                      
>       return;                                                                                                      

Changing the test in pkgAcqIndex::Custom600Headers() to be :

if (ShortDesc().find("Translation") != string::npos)

Seems to fix the issue quite nicely.  From what I can tell, this is the only
place where I found that test on 0. Other places do test with string::npos.
"

As soon as MVO is ok with this, I will SRU the modification and upload
the fix.

Kind regards,

...Louis

** Changed in: apt (Ubuntu Trusty)
       Status: Invalid => In Progress

** Changed in: apt (Ubuntu Xenial)
       Status: In Progress => Invalid

** Changed in: apt (Ubuntu Trusty)
   Importance: Undecided => Medium

** Changed in: apt (Ubuntu Xenial)
   Importance: Medium => Undecided

** Changed in: apt (Ubuntu Trusty)
     Assignee: (unassigned) => Louis Bouchard (louis-bouchard)

** Changed in: apt (Ubuntu Xenial)
     Assignee: Louis Bouchard (louis-bouchard) => (unassigned)

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You received this bug notification because you are a member of नेपाली
भाषा समायोजकहरुको समूह, which is subscribed to Xenial.
Matching subscriptions: Ubuntu 16.04 Bugs
https://bugs.launchpad.net/bugs/1625667

Title:
  Trusty: apt does not try next mirror if index file download fails with
  mirror:// source

Status in apt package in Ubuntu:
  Invalid
Status in apt source package in Trusty:
  In Progress
Status in apt source package in Xenial:
  Invalid

Bug description:
  When using the mirror://mirrors.ubuntu.com/mirrors.txt  functionality
  on Trusty, if the download of the index file fails, apt will not retry
  on another archive listed in mirrors.txt and will fail.

  Running the following on Trusty leads to the following result :

  sudo apt-get update -qq 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-security/universe/binary-amd64/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-security/main/binary-i386/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-security/restricted/binary-i386/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-security/universe/binary-i386/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-updates/main/binary-amd64/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-updates/restricted/binary-amd64/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-updates/universe/binary-amd64/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-updates/main/binary-i386/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-updates/restricted/binary-i386/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  W: Failed to fetch mirror://mirrors.ubuntu.com/mirrors.txt/dists/trusty-updates/universe/binary-i386/Packages 404 Not Found [Mirror: http://ftp.availo.se/ubuntu/] 
  E: Some index files failed to download. They have been ignored, or old ones used instead. 

  The same configuration works correctly on Xenial

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