Merge pull request ocaml#27996 from clecat/master

conf-gnuplot: Add support for windows & openbsd

Author: mseri

packages/conf-gnuplot/conf-gnuplot.0.1/opam

@@ -4,7 +4,9 @@ homepage: "http://www.gnuplot.info/"
 authors: "http://www.gnuplot.info/faq/faq.html"
 bug-reports: "https://github.com/ocaml/opam-repository/issues"
 license: "gnuplot"
-build: ["gnuplot" "--version"]
+build: [
+  ["gnuplot" "--version"] { !(os = "win32" & os-distribution = "cygwin") }
+  ["gnuplot-base.exe" "--version"] {os = "win32" & os-distribution = "cygwin"}]
 depexts: [
   ["gnuplot-x11"] {os-family = "debian"}
   ["gnuplot-x11"] {os-family = "ubuntu"}
@@ -16,6 +18,9 @@ depexts: [
   ["gnuplot"] {os-family = "suse" | os-family = "opensuse"}
   ["gnuplot"] {os-family = "arch"}
   ["gnuplot"] {os = "freebsd"}
+  ["gnuplot-base"] {os = "win32" & os-distribution = "cygwin"}
+  ["mingw-w64-x86_64-gnuplot"] {os = "win32" & os-distribution = "msys2"}
+  ["math/gnuplot"] {os = "openbsd"}
 ]
 synopsis: "Virtual package relying on gnuplot installation"
 description: """