freebsd.libsysinfo: init (#387377)

pkgs/os-specific/bsd/freebsd/pkgs/libsysinfo.nix

@@ -0,0 +1,56 @@
+{
+  lib,
+  mkDerivation,
+  fetchurl,
+  fetchFromGitHub,
+}:
+let
+  pcFile = fetchurl {
+    url = "https://raw.githubusercontent.com/freebsd/freebsd-ports/a613e66a54d54251878412b74c1e99defdac4192/devel/libsysinfo/files/libsysinfo.pc.in";
+    hash = "sha256-KeCOYLCYeoJm+AwaagygKve2f+jNaIfaO7c/UnMegAg=";
+  };
+in
+mkDerivation rec {
+  pname = "libsysinfo";
+  path = "...";
+  version = "0.0.3";
+  src = fetchFromGitHub {
+    owner = "bsdimp";
+    repo = "libsysinfo";
+    rev = "e535d95d1598932a0084a027402104d6e0276479";
+    hash = "sha256-HFgaYRR9HQM0iVJBWq1nrPGZIl/Y/5C0JJUunlzCZLI=";
+  };
+
+  outputs = [
+    "out"
+    "man"
+    "debug"
+  ];
+
+  env.NIX_LDFLAGS = "-lkvm";
+
+  # bash-sh syntax differences
+  postPatch = ''
+    substituteInPlace Makefile --replace-fail 'then else' 'then :; else'
+    substituteInPlace Makefile --replace-fail 'mkdir' 'mkdir -p'
+  '';
+
+  postInstall = ''
+    mkdir -p $out/lib/pkgconfig
+    substitute ${pcFile} $out/lib/pkgconfig/libsysinfo.pc \
+      --replace-fail '%%PREFIX%%' "$out" \
+      --replace-fail '%%COMMENT%%' "${meta.description}" \
+      --replace-fail '%%PORTVERSION%%' "${version}"
+
+    mkdir -p $out/include/sys
+    ln -s ../sysinfo.h $out/include/sys/sysinfo.h
+  '';
+
+  meta = {
+    description = "GNU libc's sysinfo port for FreeBSD";
+    homepage = "https://github.com/bsdimp/libsysinfo";
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ rhelmot ];
+    platforms = lib.platforms.freebsd;
+  };
+}