Cannot get it to compile from Github sources on macOS 10.15.5.
So, retrieve it from pgxn.
Then compile and install it.
[jerome@jeroboam] > make clang -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -Wno-unused-command-line-argument -O2 -undefined dynamic_lookup -I/usr/local/Cellar/postgresql@9.4/9.4.26/lib/pgxs/src/makefiles/../../src/pl/plpgsql/src -I. -I./ -I/usr/local/Cellar/postgresql@9.4/9.4.26/include/server -I/usr/local/Cellar/postgresql@9.4/9.4.26/include/internal -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -I/usr/local/opt/gettext/include -I/usr/local/opt/openldap/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/readline/include -I/usr/local/opt/tcl-tk/include -c -o plpgsql_check.o plpgsql_check.c clang -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -Wno-unused-command-line-argument -O2 -undefined dynamic_lookup -I/usr/local/Cellar/postgresql@9.4/9.4.26/lib/pgxs/src/makefiles/../../src/pl/plpgsql/src -bundle -multiply_defined suppress -o plpgsql_check.so plpgsql_check.o -L/usr/local/Cellar/postgresql@9.4/9.4.26/lib -L/usr/local/opt/gettext/lib -L/usr/local/opt/openldap/lib -L/usr/local/opt/openssl@1.1/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/tcl-tk/lib -Wl,-dead_strip_dylibs -bundle_loader /usr/local/Cellar/postgresql@9.4/9.4.26/bin/postgres [jerome@jeroboam] > make install /bin/sh /usr/local/Cellar/postgresql@9.4/9.4.26/lib/pgxs/src/makefiles/../../config/install-sh -c -d '/usr/local/Cellar/postgresql@9.4/9.4.26/lib' /bin/sh /usr/local/Cellar/postgresql@9.4/9.4.26/lib/pgxs/src/makefiles/../../config/install-sh -c -d '/usr/local/Cellar/postgresql@9.4/9.4.26/share/extension' /bin/sh /usr/local/Cellar/postgresql@9.4/9.4.26/lib/pgxs/src/makefiles/../../config/install-sh -c -d '/usr/local/Cellar/postgresql@9.4/9.4.26/share/extension' /usr/bin/install -c -m 755 plpgsql_check.so '/usr/local/Cellar/postgresql@9.4/9.4.26/lib/plpgsql_check.so' /usr/bin/install -c -m 644 plpgsql_check.control '/usr/local/Cellar/postgresql@9.4/9.4.26/share/extension/' /usr/bin/install -c -m 644 plpgsql_check--1.0.sql '/usr/local/Cellar/postgresql@9.4/9.4.26/share/extension/' [jerome@jeroboam] >Then from psql:
crmmbqt=# CREATE EXTENSION plpgsql_check; CREATE EXTENSION Time: 317.716 ms
