# Find Module script can’t find packages installed with MacPorts

**URL:** <https://discourse.cmake.org/t/find-module-script-can-t-find-packages-installed-with-macports/7244>\
**Category:** Code\
**Created:** [January 14, 2023, 12:42am UTC](https://discourse.cmake.org/t/find-module-script-can-t-find-packages-installed-with-macports/7244 "2023-01-14T00:42:55Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![tomoreilly](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/t/439d5e/32.png) [@tomoreilly](https://discourse.cmake.org/u/tomoreilly)\
**Post date:** [January 14, 2023, 12:42am UTC](https://discourse.cmake.org/t/find-module-script-can-t-find-packages-installed-with-macports/7244/1 "2023-01-14T00:42:55Z")

</div>

I’ve been struggling with a seemingly simple problem. My CMakeLists.txt looks for a package named “Proj”, with find\_package() and third-party-provided FindProj.cmake, but is unable to find it on MacOS when the package has been installed with MacPorts. In this case MacPorts installs the Proj headers/libraries into directory /opt/local/lib/proj\*, where ‘\*’ is a digit indicating the Proj version; e.g. my system has two Proj versions installed:

```auto
% ls -d /opt/local/lib/proj*
/opt/local/lib/proj6	/opt/local/lib/proj8

```

Neither proj6 nor proj8 provides proj\_config.cmake or ProjConfig.cmake, although newer Proj versions do. I always want to find the newest installed Proj version, so I assume  
I should call find\_package() such that it first tries the Config approach, followed by the Module approach - something like this:

`find_package(PROJ)`

But cmake is unable to find either /opt/local/lib/proj6 or /opt/local/proj8. I do have a third-party FindProj.cmake script installed but I confess I don’t really understand how it works. Can I somehow provide a “hint” to this script, e.g. tell it to look under “/opt/local/lib”? FindProj.cmake looks like this:

```auto
# Find Proj
# ~~~~~~~~~
# Copyright (c) 2007, Martin Dobias <wonder.sk at gmail.com>
# Redistribution and use is allowed according to the terms of the BSD license.
# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
#
# CMake module to search for Proj library
#
# If it's found it sets PROJ_FOUND to TRUE
# and following variables are set:
# PROJ_INCLUDE_DIR
# PROJ_LIBRARY

# FIND_PATH and FIND_LIBRARY normally search standard locations
# before the specified paths. To search non-standard paths first,
# FIND_* is invoked first with specified paths and NO_DEFAULT_PATH
# and then again with no specified paths to search the default
# locations. When an earlier FIND_* succeeds, subsequent FIND_*s
# searching for the same item do nothing.

# try to use framework on mac
# want clean framework path, not unix compatibility path
message("In FindProj() module!")
IF (APPLE)
  IF (CMAKE_FIND_FRAMEWORK MATCHES "FIRST"
      OR CMAKE_FRAMEWORK_PATH MATCHES "ONLY"
      OR NOT CMAKE_FIND_FRAMEWORK)
    SET (CMAKE_FIND_FRAMEWORK_save ${CMAKE_FIND_FRAMEWORK} CACHE STRING "" FORCE)
    SET (CMAKE_FIND_FRAMEWORK "ONLY" CACHE STRING "" FORCE)
    #FIND_PATH(PROJ_INCLUDE_DIR PROJ/proj.h)
    FIND_LIBRARY(PROJ_LIBRARY PROJ)
    IF (PROJ_LIBRARY)
      # FIND_PATH doesn't add "Headers" for a framework
      SET (PROJ_INCLUDE_DIR ${PROJ_LIBRARY}/Headers CACHE PATH "Path to a file.")
    ENDIF (PROJ_LIBRARY)
    SET (CMAKE_FIND_FRAMEWORK ${CMAKE_FIND_FRAMEWORK_save} CACHE STRING "" FORCE)
  ENDIF ()
ENDIF (APPLE)

FIND_PATH(PROJ_INCLUDE_DIR proj.h
  "$ENV{INCLUDE}"
  "$ENV{LIB_DIR}/include"
  )

FIND_LIBRARY(PROJ_LIBRARY NAMES proj_i proj PATHS
  "$ENV{LIB}"
  "$ENV{LIB_DIR}/lib"
  )

IF (PROJ_INCLUDE_DIR AND PROJ_LIBRARY)
   SET(PROJ_FOUND TRUE)
ENDIF (PROJ_INCLUDE_DIR AND PROJ_LIBRARY)

IF (PROJ_FOUND)
   IF (EXISTS ${PROJ_INCLUDE_DIR}/proj.h AND EXISTS ${PROJ_INCLUDE_DIR}/proj_experimental.h)
     FILE(READ ${PROJ_INCLUDE_DIR}/proj.h proj_version)
     STRING(REGEX REPLACE "^.*PROJ_VERSION_MAJOR +([0-9]+).*$" "\\1" PROJ_VERSION_MAJOR "${proj_version}")
     STRING(REGEX REPLACE "^.*PROJ_VERSION_MINOR +([0-9]+).*$" "\\1" PROJ_VERSION_MINOR "${proj_version}")
     STRING(REGEX REPLACE "^.*PROJ_VERSION_PATCH +([0-9]+).*$" "\\1" PROJ_VERSION_PATCH "${proj_version}")
     STRING(CONCAT PROJ_VERSION_STR "(" ${PROJ_VERSION_MAJOR} "." ${PROJ_VERSION_MINOR} "." ${PROJ_VERSION_PATCH} ")")
     IF ((PROJ_VERSION_MAJOR EQUAL 6) AND ((PROJ_VERSION_MINOR LESS 3) OR (PROJ_VERSION_MINOR EQUAL 3 AND PROJ_VERSION_PATCH LESS 1)))
       MESSAGE (FATAL_ERROR "Cannot build QGIS using Proj ${PROJ_VERSION_MAJOR}.${PROJ_VERSION_MINOR}.${PROJ_VERSION_PATCH} Use 6.3.1 or higher.")
     ENDIF ((PROJ_VERSION_MAJOR EQUAL 6) AND ((PROJ_VERSION_MINOR LESS 3) OR (PROJ_VERSION_MINOR EQUAL 3 AND PROJ_VERSION_PATCH LESS 1)))
   ELSE(EXISTS ${PROJ_INCLUDE_DIR}/proj.h AND EXISTS ${PROJ_INCLUDE_DIR}/proj_experimental.h)
     FILE(READ ${PROJ_INCLUDE_DIR}/proj.h proj_version)
     STRING(REGEX REPLACE "^.*PJ_VERSION ([0-9]+).*$" "\\1" PJ_VERSION "${proj_version}")

     # This will break if 4.10.0 ever will be released (highly unlikely)
     STRING(REGEX REPLACE "([0-9])([0-9])([0-9])" "\\1" PROJ_VERSION_MAJOR "${PJ_VERSION}")

     STRING(REGEX REPLACE "([0-9])([0-9])([0-9])" "\\2" PROJ_VERSION_MINOR "${PJ_VERSION}")
     STRING(REGEX REPLACE "([0-9])([0-9])([0-9])" "\\3" PROJ_VERSION_PATCH "${PJ_VERSION}")
     STRING(CONCAT PROJ_VERSION_STR "(" ${PROJ_VERSION_MAJOR} "." ${PROJ_VERSION_MINOR} "." ${PROJ_VERSION_PATCH} ")")

     # Minimum Proj version required is 4.9.3
     IF ((PROJ_VERSION_MAJOR EQUAL 4) AND ((PROJ_VERSION_MINOR LESS 9) OR ((PROJ_VERSION_MINOR EQUAL 9) AND (PROJ_VERSION_PATCH LESS 3))))
       MESSAGE(FATAL_ERROR "Found Proj: ${PROJ_VERSION_MAJOR}.${PROJ_VERSION_MINOR}.${PROJ_VERSION_PATCH}. Cannot build QGIS using Proj older than 4.9.3.")
     ENDIF((PROJ_VERSION_MAJOR EQUAL 4) AND ((PROJ_VERSION_MINOR LESS 9) OR ((PROJ_VERSION_MINOR EQUAL 9) AND (PROJ_VERSION_PATCH LESS 3))))
   ENDIF(EXISTS ${PROJ_INCLUDE_DIR}/proj.h AND EXISTS ${PROJ_INCLUDE_DIR}/proj_experimental.h)
   IF (NOT PROJ_FIND_QUIETLY)
     MESSAGE(STATUS "Found Proj: ${PROJ_LIBRARY} version ${PROJ_VERSION_MAJOR} ${PROJ_VERSION_STR}")
   ENDIF (NOT PROJ_FIND_QUIETLY)

   INCLUDE_DIRECTORIES(SYSTEM BEFORE ${PROJ_INCLUDE_DIR})
   ADD_DEFINITIONS(-DPROJ_VERSION_MAJOR=${PROJ_VERSION_MAJOR})

ELSE (PROJ_FOUND)

   IF (PROJ_FIND_REQUIRED)
      MESSAGE(FATAL_ERROR "Could not find Proj")
   ENDIF (PROJ_FIND_REQUIRED)

ENDIF (PROJ_FOUND)

```

---

<div class="post-metadata">

**Author:** ![ben.boeckel](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)\
**Post date:** [January 15, 2023, 2:44am UTC](https://discourse.cmake.org/t/find-module-script-can-t-find-packages-installed-with-macports/7244/2 "2023-01-15T02:44:09Z")

</div>

Are the libraries named with the version number in them? If so, that `find_library` call needs to understand that. Otherwise, adding `PATH_SUFFIXES proj5 proj6 proj7 proj8` should help.

For more robustness and future-proofing, having a list of these suffixes set by something like:

```cmake
set(Proj_LIBRARY_DIR_SUFFXES ${Proj_LIBRARY_DIR_EXTRA_SUFFXES} 8 7 6 5)

```

and then building that `PATH_SUFFIXES` argument up from this would work better.