On 7/31/17 15:17, Peter Eisentraut wrote:
> On 7/31/17 14:55, Tom Lane wrote:
>>> We use the "PATH" variants when we need a fully qualified name. For
>>> example, at some point or another, we needed to substitute a fully
>>> qualified perl binary name into the headers of scripts.
>>
>>> If there is no such requirement, then we should use the non-PATH variants.
>>
>> Why? That risks failures of various sorts, and you have not stated
>> any actual benefit of it.
>
> What I wrote is merely a description of the current practice. That
> practice was in turn developed out of ancient Autoconf standard
> practices. There are arguments to be made for doing it differently.
>
> One major PITA with the AC_PATH_* checks is that you can only override
> them with environment variables that are full paths; otherwise the
> environment variables are ignored. For example, currently, running
>
> ./configure PYTHON=python3
>
> will result in the PYTHON setting being ignored. Currently, this only
> affects a small number of variables, but if we expanded that, it would
> be a pretty significant usability change.
Plus certain special macros such as AC_PROG_CC don't have a PATH
variant, so you're always going to have some inconsistencies.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
