I'm using the same makefile I had for firebird 1, which is below
but now (1.5) I get

gcc udflocal.c -fPIC -c -w -I/opt/firebird/include udflocal.so
gcc: udflocal.so: No such file or directory
make: *** [udflocal.so] Error 1

here is the makefile

# The contents of this file are subject to the Interbase Public
# License Version 1.0 (the "License"); you may not use this file
# except in compliance with the License. You may obtain a copy
# of the License at http://www.Inprise.com/IPL.html
#
# Software distributed under the License is distributed on an
# "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
# or implied. See the License for the specific language governing
# rights and limitations under the License.
#
# The Original Code was created by Inprise Corporation
# and its predecessors. Portions created by Inprise Corporation are
# Copyright (C) Inprise Corporation.
#
# All Rights Reserved.
# Contributor(s): ______________________________________.

# -------------------------- makefile ----------------------------
#
# This makefile will build the examples supplied with InterBase 5.0.
# See the Programmer's Guide for information about the example
# databases and example programs.
#
# You should edit the IBASE definition in this file to point to the
# directory where InterBase was installed. Or you can specify the
# definition on the command-line of make.
#
# To build all the examples use the 'all' target, by issuing the
# following command:
#
# make all
# or
# make IBASE=/usr/interbase all
#
# To build any one individual target, use the following command:
#
# make 'target'
# or
# make IBASE=/usr/interbase 'target'
#
# where target 'target' is one of the following:
# employe2.gdb, api1, api2, api3, api4, api5, api6, api7,
# api8, api9, api9f, api10, api11, api12, api13, api14,
# api15, api16, api16t, apifull, dyn1, dyn2, dyn3, dyn4,
# dyn5, dynfull, stat1, stat2, stat3, stat4, stat5,
# stat6, stat7, stat8, stat9, stat10, stat11, stat12,
# stat12t, udflocal
#
# ---------------------------------------------------------------------

# ---------------------------------------------------------------------
# InterBase Installation Directory
#
# CHANGE this definition to point to your InterBase installation directory
# ---------------------------------------------------------------------
IBASE= /opt/firebird

# ---------------------------------------------------------------------
# General InterBase Defines for Linux
# ---------------------------------------------------------------------
GPRE= $(IBASE)/bin/gpre -c -n
GPRE_M= $(IBASE)/bin/gpre -c -n -m
ISQL= $(IBASE)/bin/isql
DB= employee.gdb

# ---------------------------------------------------------------------
# General Compiler and linker Defines for Linux
# ---------------------------------------------------------------------
CC= gcc
LINK= gcc
LIB_LINK= ld
CFLAGS= -c -w -I$(IBASE)/include
LIB_CFLAGS= -fPIC $(CFLAGS)
LINK_FLAGS= -lgds -ldl -lcrypt
LIB_LINK_FLAGS= -shared -lgds
RM= rm -f

# The contents of this file are subject to the Interbase Public
# License Version 1.0 (the "License"); you may not use this file
# except in compliance with the License. You may obtain a copy
# of the License at http://www.Inprise.com/IPL.html
#
# Software distributed under the License is distributed on an
# "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
# or implied. See the License for the specific language governing
# rights and limitations under the License.
#
# The Original Code was created by Inprise Corporation
# and its predecessors. Portions created by Inprise Corporation are
# Copyright (C) Inprise Corporation.
#
# All Rights Reserved.
# Contributor(s): ______________________________________.
# ---------------------------------------------------------------------
# Generic Compilation Rules
#
# Do NOT change anything below this point.
# ---------------------------------------------------------------------
SUFFIXES: .o .c .e

e.c:
$(GPRE) $< -d $(DB)

c.o:
$(CC) $< $(CFLAGS) $@

o:
$(LINK) -o $@ $< $(LINK_FLAGS)

# ---------------------------------------------------------------------
# Specific targets to build
# ---------------------------------------------------------------------

all: udflocal

udflocal.so: udflocal.c example.h
$(CC) $< $(LIB_CFLAGS) $@

udflocal: udflocal.so
$(LIB_LINK) $@.o -o $@ $(LIB_LINK_FLAGS)
@echo ------------------------------------------------------
@echo You need to copy udflocal to the interbase lib directory
@echo in order for the server to load it.
@echo ------------------------------------------------------

--
Nick
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