3.0.0rc1 build failure on Ubuntu xenial: gserialized_estimate.o: undefined reference to symbol 'roundf@@GLIBC_2.2.5'

[myon]

3.0.0rc1 fails on Ubuntu xenial, all architectures covered by apt.postgresql.org. (Other Debian/Ubuntu distributions build fine.)

amd64:

13:27:23 gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fPIC -pie -fno-omit-frame-pointer -fPIC -shared -o postgis-3.so postgis_module.o lwgeom_accum.o lwgeom_spheroid.o lwgeom_ogc.o lwgeom_functions_analytic.o lwgeom_inout.o lwgeom_functions_basic.o lwgeom_btree.o lwgeom_box.o lwgeom_box3d.o lwgeom_geos.o lwgeom_sfcgal.o lwgeom_geos_prepared.o lwgeom_geos_clean.o lwgeom_geos_relatematch.o lwgeom_export.o lwgeom_in_gml.o lwgeom_in_kml.o lwgeom_in_geohash.o lwgeom_in_geojson.o lwgeom_in_encoded_polyline.o lwgeom_triggers.o lwgeom_dump.o lwgeom_dumppoints.o lwgeom_functions_lrs.o lwgeom_functions_temporal.o lwgeom_rectree.o long_xact.o lwgeom_sqlmm.o lwgeom_rtree.o lwgeom_transform.o lwgeom_window.o gserialized_typmod.o gserialized_gist_2d.o gserialized_gist_nd.o gserialized_supportfn.o gserialized_spgist_2d.o gserialized_spgist_3d.o gserialized_spgist_nd.o brin_2d.o brin_nd.o brin_common.o gserialized_estimate.o geography_inout.o geography_btree.o geography_centroid.o geography_measurement.o geography_measurement_trees.o geometry_inout.o postgis_libprotobuf.o vector_tile.pb-c.o geobuf.pb-c.o mvt.o lwgeom_out_mvt.o geobuf.o lwgeom_out_geobuf.o lwgeom_out_geojson.o postgis_legacy.o -L/usr/lib/x86_64-linux-gnu  -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -L/usr/lib/llvm-6.0/lib  -L/usr/lib/x86_64-linux-gnu/mit-krb5 -Wl,--as-needed  ../deps/wagyu/libwagyu.la -lstdc++ ../libpgcommon/libpgcommon.a ../liblwgeom/.libs/liblwgeom.a  -L/usr/lib/x86_64-linux-gnu -lgeos_c -lproj -ljson-c -lprotobuf-c -lxml2 -L/usr/lib/x86_64-linux-gnu -lSFCGAL -Wl,--exclude-libs,ALL -Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now -L/usr/lib/x86_64-linux-gnu -lSFCGAL 
13:27:24 /usr/bin/ld: gserialized_estimate.o: undefined reference to symbol 'roundf@@GLIBC_2.2.5'
13:27:24 //lib/x86_64-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line
13:27:24 collect2: error: ld returned 1 exit status
13:27:24 /usr/lib/postgresql/11/lib/pgxs/src/makefiles/../../src/Makefile.shlib:309: recipe for target 'postgis-3.so' failed

i386 (and ppc64el):

13:29:32 gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fPIC -pie -fPIC -shared -o postgis-3.so postgis_module.o lwgeom_accum.o lwgeom_spheroid.o lwgeom_ogc.o lwgeom_functions_analytic.o lwgeom_inout.o lwgeom_functions_basic.o lwgeom_btree.o lwgeom_box.o lwgeom_box3d.o lwgeom_geos.o lwgeom_sfcgal.o lwgeom_geos_prepared.o lwgeom_geos_clean.o lwgeom_geos_relatematch.o lwgeom_export.o lwgeom_in_gml.o lwgeom_in_kml.o lwgeom_in_geohash.o lwgeom_in_geojson.o lwgeom_in_encoded_polyline.o lwgeom_triggers.o lwgeom_dump.o lwgeom_dumppoints.o lwgeom_functions_lrs.o lwgeom_functions_temporal.o lwgeom_rectree.o long_xact.o lwgeom_sqlmm.o lwgeom_rtree.o lwgeom_transform.o lwgeom_window.o gserialized_typmod.o gserialized_gist_2d.o gserialized_gist_nd.o gserialized_supportfn.o gserialized_spgist_2d.o gserialized_spgist_3d.o gserialized_spgist_nd.o brin_2d.o brin_nd.o brin_common.o gserialized_estimate.o geography_inout.o geography_btree.o geography_centroid.o geography_measurement.o geography_measurement_trees.o geometry_inout.o postgis_libprotobuf.o vector_tile.pb-c.o geobuf.pb-c.o mvt.o lwgeom_out_mvt.o geobuf.o lwgeom_out_geobuf.o lwgeom_out_geojson.o postgis_legacy.o -L/usr/lib/i386-linux-gnu  -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -L/usr/lib/llvm-6.0/lib  -L/usr/lib/i386-linux-gnu/mit-krb5 -Wl,--as-needed  ../deps/wagyu/libwagyu.la -lstdc++ ../libpgcommon/libpgcommon.a ../liblwgeom/.libs/liblwgeom.a  -L/usr/lib/i386-linux-gnu -lgeos_c -lproj -ljson-c -lprotobuf-c -lxml2 -L/usr/lib/i386-linux-gnu -lSFCGAL -Wl,--exclude-libs,ALL -Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now -L/usr/lib/i386-linux-gnu -lSFCGAL 
13:29:32 /usr/bin/ld: ../liblwgeom/.libs/liblwgeom.a(measures.o): undefined reference to symbol 'hypot@@GLIBC_2.0'
13:29:32 //lib/i386-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line
13:29:32 collect2: error: ld returned 1 exit status
13:29:32 /usr/lib/postgresql/11/lib/pgxs/src/makefiles/../../src/Makefile.shlib:309: recipe for target 'postgis-3.so' failed

Full logs: ​https://pgdgbuild.dus.dg-i.net/view/Binaries/job/postgis-binaries/241/architecture=amd64,distribution=xenial/console ​https://pgdgbuild.dus.dg-i.net/view/Binaries/job/postgis-binaries/architecture=i386,distribution=xenial/241/console

[Algunenano]

As liblwgeom is now linked statically we might need to explicitly add -lm to the libraries (postgis-3.so and so on). Can you test manually adding it to the LDFLAGS during configure, please?

[Algunenano]

​https://github.com/postgis/postgis/pull/491 might fix this issue.

All my systems were already working without the patch (including a Xenial VM) so it'd nice if you could confirm it before merging.

[myon]

Replying to Algunenano:

All my systems were already working without the patch (including a Xenial VM) so it'd nice if you could confirm it before merging.

The difference might be that dpkg-buildpackage uses additional compiler flags compared to a "plain" build, cf. dpkg-buildflags. I'd especially suspect LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro to make a difference in this area.

[Algunenano]

I can confirm that when I run the exact same command (removing sfcgal because I don't have it installed) in the Xenial VM I get the same error, so it looks it has to do with some linker options.

[Algunenano]

The issue goes again once I remove the -pie flag. I'm not sure why it's there since it is used to produce executables, so I'm investigating where it comes from and what can we do to suppress it.

[myon]

This turned out to be my fault. We had previously disabled PIE on Ubuntu because it caused trouble, but then I removed that logic, neglecting the fact that it's still necessary.

​https://salsa.debian.org/debian-gis-team/postgis/commit/50866f4d2d161515899ddf2e041dce3d52c03aba

I put it back now for xenial; bionic seems fine.