Re: [boost] big problem with dependency changes

Subject: Re: [boost] big problem with dependency changes
From: Bjørn Roald (bjorn_at_[hidden])
Date: 2014-06-16 12:28:23

On 06/16/2014 12:11 PM, Peter Dimov wrote:
> Glen Fernandes wrote:
>> On Mon, Jun 16, 2014 at 1:28 AM, Paul A. Bristow wrote:
>> > I'm glad I am not alone in having to nuke the /boost directory.
>> >
>> > Am I right to be worried about this?  It should not happen?  Why
>> does it > happen?
>>
>> I've had no problems on my non-Windows (Linux, OSX) machines. I
>> regularly have to nuke /boost on Windows to get things to work.
>
> I'm on Windows and b2 has done a good job so far. I've only had to
> delete /boost maybe once. I usually don't even bother with "b2 headers"
> - everything seems to work without it. Go figure. :-)

For those of you that struggle with this when you use b2 on your system, 
You should get a line at the beginning of the output saying:

     - symlinks supported       : yes

If not, b2 is not able to create symbolic links for individual files on 
your system.  There may be a number of reasons for this, but on recent 
MS Windows systems it is usually related to user privileges, the tool 
used to create symbolic links require elevated privileges.

If b2 are not able to create symbolic links for "b2 headers" targets, it 
will use hard links or file copies.  Both of these alternatives to 
symbolic links have severe issues that could cause you to end up with 
stale files in the boost folder, or cause you to edit files that are 
later overwritten by b2.

For enabling b2 use of symbolic links on windows, have a look at the 
following information from the web (quoting from my posting 2 February 
on the same issue.):

refs:
http://stackoverflow.com/questions/15320550/secreatesymboliclinkprivilege-ignored-on-windows-8

http://msdn.microsoft.com/en-us/library/bb530410.aspx

http://superuser.com/questions/148937/windows-server-2008-create-symbolic-link-updated-security-policy-still-gives-pr

http://superuser.com/questions/124679/how-do-i-create-a-link-in-windows-7-home-premium-as-a-regular-user

Most promising may be:
Provide SeCreateSymbolicLinkPrivilege privilege to the user who is
running the script. If the user is Administrator on the machine you may
need to turn off UAC.

Note I have not tested any of this as I have no problems on my systems. 
  So please give feedback to the list if any of this work for you.  Thanks.

--
Bjørn