Cannot exec() program outside of /bin if PATH is unset

[Christian Franke]

Corinna Vinschen wrote:
> On Oct 17 11:10, Corinna Vinschen wrote:
>> On Oct 16 23:51, Christian Franke wrote:
>>> Corinna Vinschen wrote:
>>>> ...
>>>> I implemented this in the latest snapshot.  It calls SetDllDirectory
>>>> on Cygwin's /bin, and dlopen addiotnally tries to load the DLL with
>>>> LoadLibraryEx(LOAD_WITH_ALTERED_SEARCH_PATH) if all else failed.
>>> For some reason, the SetDllDirectory() call has no effect for exec():
>>>
>>> Testcase:
>>>
>>> $ unset PATH
>>>
>>> $ uname -srvm
>>> -bash: uname: No such file or directory
>>>
>>> $ /bin/uname -srvm
>>> CYGWIN_NT-6.1-WOW64 1.7.33s(0.277/5/3) 20141014 19:44:03 i686
>>>
>>> $ /usr/sbin/alternatives
>>> /usr/sbin/alternatives: error while loading shared libraries: ?: cannot open
>>> shared object file: No such file or directory
>> Weird.  The same sequence of commands works fine for me on W8,
>> W8.1 and W10 64 bit, under i686 as well as x86_64 Cygwin.
>>
>> [...]
>>
>> but it doesn't on Vista and W7, wow.
>>
>> The question now is, is it because the path given to SetDllDirectory
>> is not propagated to child processes on older systems, or is it
>> because the directory is only used in calls to LoadLibrary{Ex} on
>> older systems.
>>
>> Stay tuned, I have to investigate this.
> Ok, so prior to W8, the SetDllDirectory path is not propagated to child
> processes :-|
>
> I created a patch and a new snapshot on https://cygwin.com/snapshots/
> which calls SetDllDirectory during initialization of every process.
> Please give it a try.

Now works.

cygwin_patches_for_postfix_count++; postfix_patches_for_cygwin_count--; :-)

Thanks,
Christian


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