Make it clearer which minimal versions of cmake and nlopt are required.

Closes #100.

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: nloptr
 Type: Package
 Title: R Interface to NLopt
-Version: 2.0.0
+Version: 2.0.0.9000
 Authors@R: c(person("Jelmer", "Ypma", role = "aut",
                     email = "uctpjyy@ucl.ac.uk"),
              person(c("Steven", "G."), "Johnson", role = "aut",
@@ -38,8 +38,8 @@ Description:
     'rwinlib' for 'R <= 4.1.x' or grabbed from the 'Rtools42 toolchain' for 
     'R >= 4.2.0'.
 License: LGPL (>= 3)
-SystemRequirements: cmake (for building from included source, i.e. on macOS 
-    or on Linux if no system build, version >= 2.7.0, is found)
+SystemRequirements: cmake (>= 3.15.0) which is used only on Linux or macOS 
+    systems when no system build of nlopt (>= 2.7.0) can be found.
 Biarch: true
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)

NEWS.md

@@ -1,3 +1,7 @@
+# nloptr 2.0.0.9000
+
+* Update `SystemRequirements` description to make it clearer which minimal versions of `cmake` (`>= 3.15.0`) and `nlopt` (`>= 2.7.0`) are required (#100, @HenrikBengtsson).
+
 # nloptr 2.0.0
 
 ## Major changes

README.Rmd

@@ -42,7 +42,7 @@ On Windows, either the latest version `2.7.1` of [NLopt](https://nlopt.readthedo
 On Unix-like platforms, we use `pkg-config` to find a suitable system build of [NLopt](https://nlopt.readthedocs.io/en/latest/) (i.e. with version `>= 2.7.0`).
 
 - If it is found it is used.
-- Otherwise, [NLopt](https://nlopt.readthedocs.io/en/latest/) 2.7.1 is built from included sources using [CMake](https://cmake.org). In this case, a binary  of [CMake](https://cmake.org) stored in environment variable `CMAKE_BIN` is searched on the `PATH` and, alternatively, on a macOS-specific location. If that variable cannot be set, install will abort suggesting ways of installing [CMake](https://cmake.org).
+- Otherwise, [NLopt](https://nlopt.readthedocs.io/en/latest/) 2.7.1 is built from included sources using [CMake](https://cmake.org). In this case, a binary  of [CMake](https://cmake.org) stored in environment variable `CMAKE_BIN` is searched on the `PATH` and, alternatively, on a macOS-specific location. If that variable cannot be set, install will abort suggesting ways of installing [CMake](https://cmake.org). The minimal version requirement on `cmake` is `>= 3.15.0`.
 
 ### Installing [CMake](https://cmake.org) (macOS and Linux only)
 

README.md

@@ -56,7 +56,8 @@ version `>= 2.7.0`).
     environment variable `CMAKE_BIN` is searched on the `PATH` and,
     alternatively, on a macOS-specific location. If that variable cannot
     be set, install will abort suggesting ways of installing
-    [CMake](https://cmake.org).
+    [CMake](https://cmake.org). The minimal version requirement on
+    `cmake` is `>= 3.15.0`.
 
 ### Installing [CMake](https://cmake.org) (macOS and Linux only)