https://issues.dlang.org/show_bug.cgi?id=14828

Timothee Cour <timothee.cour2@gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |timothee.cour2@gmail.com

--- Comment #1 from Timothee Cour <timothee.cour2@gmail.com> ---
digger bisect returns:

2015-07-26T13:16:37.992:common.d:log:25 digger: bisect.d:113
ba17fa7669885dca1c8f7b246483149d37b3f10d is the first bad commit
commit ba17fa7669885dca1c8f7b246483149d37b3f10d
Author: Martin Nowak <code@dawg.eu>
Date:   Tue Mar 31 04:43:51 2015 +0200

    phobos: Merge pull request #2956 from jmdavis/tempFile

    https://github.com/D-Programming-Language/phobos/pull/2956

    Implement issue# 13996. Add File.tempFile.

Although this may just be a side effect of another root cause?

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #2 from Timothee Cour <timothee.cour2@gmail.com> ---
using different parameters for digger bisect:

bad = master @ 1 month ago
good = master @ 2 months ago

returns:

digger: bisect.d:113 f1bf3d208546728d433de7b3d53631497846b117 is the first bad
commit
commit f1bf3d208546728d433de7b3d53631497846b117
Author: Dmitry Olshansky <dmitry.olsh@gmail.com>
Date:   Fri Jun 26 20:08:27 2015 +0300

    phobos: Merge pull request #3443 from
CyberShadow/pull-20150626-091553-uni-stray-stdio-import

    https://github.com/D-Programming-Language/phobos/pull/3443

    std.uni: Remove stray std.stdio import

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #3 from Timothee Cour <timothee.cour2@gmail.com> ---
Is the root cause a symbol that should've been a weak symbol?

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #4 from Kenji Hara <k.hara.pg@gmail.com> ---
Equivalent link failure happens in win32/64.
But the regression version is not same:

With 2.064, 2.065, 2.066.0, 2.066.1
--> no problem happens

With 2.067.0, 2.067.1, 2.068.0-beta1, 2.068.0-beta2, git-head
--> duplicated symbol error happens with 'make all1_order_flipped'

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https://issues.dlang.org/show_bug.cgi?id=14828

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
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                 CC|                            |code@dawg.eu

--- Comment #5 from Martin Nowak <code@dawg.eu> ---
(In reply to Timothee Cour from comment #0)
> This bug is very annoying as it prevents partial recompilation

There are many catches with that.

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #6 from Martin Nowak <code@dawg.eu> ---
This might have the same cause as issue 14748.

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #7 from Kenji Hara <k.hara.pg@gmail.com> ---
Created attachment 1534
  --> https://issues.dlang.org/attachment.cgi?id=1534&action=edit
Win32 reduced case without Phobos dependency

(In reply to Kenji Hara from comment #4)
> Equivalent link failure happens in win32/64.
> But the regression version is not same:
> 
> With 2.064, 2.065, 2.066.0, 2.066.1
> --> no problem happens
> 
> With 2.067.0, 2.067.1, 2.068.0-beta1, 2.068.0-beta2, git-head
> --> duplicated symbol error happens with 'make all1_order_flipped'

In win32, the attached reduced case fails from 2.067. It was introduced in:

> commit 679929fa2da120db76d91303efd2316370970d1e
> Merge: 430bdba 706aa61
> Author: Andrei Alexandrescu <andrei@erdani.com>
> Date:   Wed Jan 28 08:44:07 2015 -0800
> 
>     Merge pull request #4354 from 9rnsr/fix14044
> 
>     [REG2.066] Issue 14044 - dmd generates spurious functions in object file created from empty module

However, I don't understand why the change introduced the bug...

Furthermore, I'm not sure that's really same with the original issue, because it happens from 2.068-beta2 in OSX.

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #8 from Martin Nowak <code@dawg.eu> ---
(In reply to Timothee Cour from comment #3)
> Is the root cause a symbol that should've been a weak symbol?

ModuleInfos aren't weak symbols.
You didn't past the error message. Which ModuleInfo is duplicated?
I guess it's either foo2 or main.

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #9 from Timothee Cour <timothee.cour2@gmail.com> ---
(In reply to Martin Nowak from comment #8)
> (In reply to Timothee Cour from comment #3)
> > Is the root cause a symbol that should've been a weak symbol?
> 
> ModuleInfos aren't weak symbols.
> You didn't past the error message. Which ModuleInfo is duplicated?
> I guess it's either foo2 or main.


duplicate symbol _D4foo212__ModuleInfoZ in:
    out.o
    libproj6.a(foo2.o)
ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

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https://issues.dlang.org/show_bug.cgi?id=14828

--- Comment #10 from Timothee Cour <timothee.cour2@gmail.com> ---
(In reply to Martin Nowak from comment #5)
> (In reply to Timothee Cour from comment #0)
> > This bug is very annoying as it prevents partial recompilation
> 
> There are many catches with that.

I'm well aware. However this technique, when properly used, allows very fast recompilation. We should not prevent this.

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