On Wed, Feb 24, 2021 at 02:17:14PM -0000, Stuart Henderson wrote: > On 2021-02-23, Bob <obs...@protonmail.com> wrote: > > Hi, > > > > I am trying to make a custom build of libpng in my home directory, > > using a libz build that I made in my home directory also. > > > > Both are latest version, libpng 1.6.37 same as OpenBSD's port > > https://cvsweb.openbsd.org/ports/graphics/png/Makefile?rev=1.125&content-type=text/x-cvsweb-markup > > and libz the latest one they published. For zlib it's 1.2.11 > > from http://zlib.net/ from 2017, OpenBSD does not have a port but > > base bundles a 2009 version. Since 2009, significantly an export > > "inflateReset2" has been added. > > As you have seen it is difficult to have library functions in one > version in base and in another version built elsewhere (whether that's > in $HOME or in ports). Ports only does this for libraries where there's > really no other choice and where that has been done they're used *very* > rarely (the port can then not depend on any libraries which pull in the > library from base). Currently that is libbind (used only by asdig and > zeek) and openssl (used as a static library by sslscan, and dynamic > for nrpe and nsca-ng). > > > I'll start with the detail problem, and discuss the reproduction at the > > bottom: > > > > > > This has brought me to the bizarre issue that the libpng build plainly > > refuses to link to my custom libz file /home/myuser/lib/libz.so.1 . > > Instead, it insists with linking to the OS' global > > /usr/lib/libz.so.5.0 . > > This is as expected really, it looks for the higher library version > number.
Not really, it's more that you have to make sure to put your own directory before the system directory, which requires a bit more magic than just -L. (remember that linking will stop at the first directory with a satisfying library, and link with the highest version number found in there, which is fortunate for stuff like libtool!)
