Fix conf-unwind on os-family=ubuntu

Author: jmid

packages/conf-unwind/conf-unwind.1/opam

@@ -0,0 +1,22 @@
+opam-version: "2.0"
+maintainer: "David Allsopp <[email protected]>"
+homepage: "https://www.nongnu.org/libunwind/"
+bug-reports: "https://github.com/ocaml/opam-repository/issues"
+authors: ["David Mosberger, Dave Watson, et al"]
+license: "MIT"
+build: [["pkg-config" "--short-errors" "--print-errors" "libunwind"]]
+depends: ["conf-pkg-config" {build}]
+depexts: [
+  ["libunwind-dev"] {os-family = "debian"}
+  ["libunwind-dev"] {os-family = "ubuntu"}
+  ["libunwind-devel"] {os-distribution = "centos"}
+  ["libunwind-devel"] {os-distribution = "rhel"}
+  ["libunwind-devel"] {os-distribution = "fedora"}
+  ["libunwind-dev"] {os-distribution = "alpine"}
+  ["libunwind-headers"] {os-distribution = "homebrew" & os = "macos"}
+]
+synopsis: "Virtual package relying on libunwind"
+description:"
+This package can only install if libunwind is installed on the system.
+"
+flags: conf