https://github.com/dfandrich/gpscorrelate/pull/32.patch
From 39545902a28813c3c877ea8083db6c0e8f4f5023 Mon Sep 17 00:00:00 2001
From: Nicolas PARLANT <nicolas.parlant@parhuet.fr>
Date: Thu, 3 Jul 2025 10:50:23 +0200
Subject: [PATCH] adapt Makefile for dist-building

some dists needs to declare some variables for building package
add ?= where it's useful

separate install for earch target

leave only linker flags in LDFLAGS

Signed-off-by: Nicolas PARLANT <nicolas.parlant@parhuet.fr>
---
 Makefile | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/Makefile b/Makefile
index 93bb9a9..d57a52c 100644
--- a/Makefile
+++ b/Makefile
@@ -2,13 +2,13 @@
 
 PACKAGE_VERSION = 2.3.1git
 
-CC = gcc
-CXX = g++
+CC ?= gcc
+CXX ?= g++
 EXEEXT =
-PKG_CONFIG=pkg-config
-CFLAGS   = -Wall -O2
-CXXFLAGS = $(CFLAGS)
-LDFLAGS  = -Wall -O2 -lm
+PKG_CONFIG ?= pkg-config
+CFLAGS   ?= -Wall -O2
+CXXFLAGS ?= $(CFLAGS)
+LDFLAGS  += -lm
 GTK      = 3
 CHECK_OPTIONS=
 
@@ -28,19 +28,19 @@ CFLAGSINC += $(GTKFLAGS)
 # Put --nonet here to avoid downloading DTDs while building documentation
 XSLTFLAGS =
 
-prefix   = /usr/local
+prefix   ?= /usr/local
 bindir   = $(prefix)/bin
 datadir  = $(prefix)/share
 mandir   = $(datadir)/man
-docdir   = $(datadir)/doc/gpscorrelate
+docdir   ?= $(datadir)/doc/gpscorrelate
 applicationsdir = $(datadir)/applications
 localedir = $(datadir)/locale
 
 DEFS = -DPACKAGE_VERSION=\"$(PACKAGE_VERSION)\" -DPACKAGE_LOCALE_DIR=\"$(localedir)\" -DPACKAGE_DOC_DIR=\"$(docdir)\"
 
-TARGETS = gpscorrelate-gui$(EXEEXT) gpscorrelate$(EXEEXT) doc/gpscorrelate.1 doc/gpscorrelate.html
+TARGETS ?= gpscorrelate-gui$(EXEEXT) gpscorrelate$(EXEEXT)
 
-all:	$(TARGETS)
+all:   $(TARGETS) docs
 
 gpscorrelate$(EXEEXT): $(COBJS)
 	$(CXX) -o $@ $(COBJS) $(LDFLAGS) $(LIBS)
@@ -66,9 +66,9 @@ clean:
 distclean: clean clean-po
 	rm -f AUTHORS
 
-install: all
+install-gpscorrelate:
 	install -d $(DESTDIR)$(bindir)
-	install -m 0755 gpscorrelate$(EXEEXT) gpscorrelate-gui$(EXEEXT) $(DESTDIR)$(bindir)
+	install -m 0755 gpscorrelate$(EXEEXT) $(DESTDIR)$(bindir)
 	install -d $(DESTDIR)$(mandir)/man1
 	install -m 0644 doc/gpscorrelate.1 $(DESTDIR)$(mandir)/man1
 	install -d $(DESTDIR)$(docdir)
@@ -82,6 +82,12 @@ install-desktop-file:
 	install -d $(DESTDIR)$(datadir)/icons/hicolor/scalable/apps
 	install -p -m 0644 gpscorrelate-gui.svg $(DESTDIR)$(datadir)/icons/hicolor/scalable/apps/gpscorrelate-gui.svg
 
+install-gpscorrelate-gui: install-desktop-file
+	install -d $(DESTDIR)$(bindir)
+	install -m 0755 gpscorrelate-gui$(EXEEXT) $(DESTDIR)$(bindir)
+
+install: all $(foreach target,$(TARGETS),install-$(target))
+
 docs: doc/gpscorrelate.1 doc/gpscorrelate.html
 
 # BSD make doesn't work with $< as the prerequisite in the following rules but $? is fine