poco: add checkPhase

This executes at least part of the testsutie.

All testsuites that require a service running in the background
(Postgress, MongoDB, MariaDB, ...) have been skipped. If one attempts to
run them, this likely requires a nixosTest to do so and provide the
dependencies.

Some tests I had to skip, because they break on darwin. Perhaps fixes
for theste test can be developed and upstreamed, but that requires more
expertise than I possess.

pkgs/by-name/po/poco/disable-broken-tests.patch

@@ -0,0 +1,21 @@
+diff --git a/Data/testsuite/src/DataTest.cpp b/Data/testsuite/src/DataTest.cpp
+index a78c4e5..e8d9335 100644
+--- a/Data/testsuite/src/DataTest.cpp
++++ b/Data/testsuite/src/DataTest.cpp
+@@ -1652 +1652 @@ CppUnit::Test* DataTest::suite()
+-	CppUnit_addTest(pSuite, DataTest, testSQLChannel);
++	// CppUnit_addTest(pSuite, DataTest, testSQLChannel);
+diff --git a/Net/testsuite/src/HTTPClientSessionTest.cpp b/Net/testsuite/src/HTTPClientSessionTest.cpp
+index 31de150..b5c0d13 100644
+--- a/Net/testsuite/src/HTTPClientSessionTest.cpp
++++ b/Net/testsuite/src/HTTPClientSessionTest.cpp
+@@ -406 +406 @@ CppUnit::Test* HTTPClientSessionTest::suite()
+-	CppUnit_addTest(pSuite, HTTPClientSessionTest, testGetSmallUnix);
++	// CppUnit_addTest(pSuite, HTTPClientSessionTest, testGetSmallUnix);
+diff --git a/Net/testsuite/src/SocketTest.cpp b/Net/testsuite/src/SocketTest.cpp
+index 27c1800..9bd684b 100644
+--- a/Net/testsuite/src/SocketTest.cpp
++++ b/Net/testsuite/src/SocketTest.cpp
+@@ -900 +900 @@ CppUnit::Test* SocketTest::suite()
+-	CppUnit_addTest(pSuite, SocketTest, testEchoUnixLocal);
++	// CppUnit_addTest(pSuite, SocketTest, testEchoUnixLocal);

pkgs/by-name/po/poco/package.nix

@@ -54,10 +54,23 @@ stdenv.mkDerivation rec {
   MYSQL_DIR = libmysqlclient;
   MYSQL_INCLUDE_DIR = "${MYSQL_DIR}/include/mysql";
 
-  cmakeFlags = [
-    # use nix provided versions of sqlite, zlib, pcre, expat, ... instead of bundled versions
-    (lib.cmakeBool "POCO_UNBUNDLED" true)
-  ];
+  cmakeFlags =
+    let
+      # These tests require running services, which the checkPhase is ill equipeed to provide
+      # TODO get them running in a nixosTest
+      excludeTestsRegex = lib.concatStringsSep "|" [
+        "Redis"
+        "DataODBC"
+        "MongoDB"
+        "DataMySQL"
+      ];
+    in
+    [
+      # use nix provided versions of sqlite, zlib, pcre, expat, ... instead of bundled versions
+      (lib.cmakeBool "POCO_UNBUNDLED" true)
+      (lib.cmakeBool "ENABLE_TESTS" true)
+      (lib.cmakeFeature "CMAKE_CTEST_ARGUMENTS" "--exclude-regex;'${excludeTestsRegex}'")
+    ];
 
   patches = [
     # Remove on next release
@@ -67,8 +80,16 @@ stdenv.mkDerivation rec {
       url = "https://patch-diff.githubusercontent.com/raw/pocoproject/poco/pull/4879.patch";
       hash = "sha256-VFWuRuf0GPYFp43WKI8utl+agP+7a5biLg7m64EMnVo=";
     })
+    # failing on darwin, could perhaps be patched / a fix upstreamed later
+    ./disable-broken-tests.patch
   ];
 
+  doCheck = true;
+  preCheck = ''
+    # workaround for some tests trying to write to /homeless-shelter
+    export HOME=$(mktemp -d)
+  '';
+
   postFixup = ''
     grep -rlF INTERFACE_INCLUDE_DIRECTORIES "$dev/lib/cmake/Poco" | while read -r f; do
       substituteInPlace "$f" \