Python: optional dependencies and post-installation tests (#10335)

* Add post-installation tests to Python package

* libbsd does not build on macOS

* Make Python dependencies optional

* Add readline dep, remove ncurses patch, fix autoreconf

var/spack/repos/builtin/packages/cdecimal/darwin_install_name.patch

@@ -0,0 +1,24 @@
+diff -Naur a/Makefile.in b/Makefile.in
+--- a/Makefile.in	2019-01-13 17:43:38.000000000 -0600
++++ b/Makefile.in	2019-01-13 17:44:25.000000000 -0600
+@@ -101,7 +101,7 @@
+ 	ranlib $(LIBSTATIC)
+ 
+ $(LIBSHARED): Makefile vars.mk $(OBJS)
+-	$(LD) $(LDFLAGS) -shared -Wl,-soname,$(LIBSONAME) -o $(LIBSHARED) $(OBJS) -lm
++	$(LD) $(LDFLAGS) -shared -Wl,-install_name,$(LIBSONAME) -o $(LIBSHARED) $(OBJS) -lm
+ 
+ 
+ $(NEWVARS):
+diff -Naur a/configure b/configure
+--- a/configure	2019-01-13 17:43:38.000000000 -0600
++++ b/configure	2019-01-13 17:43:56.000000000 -0600
+@@ -2385,7 +2385,7 @@
+ 
+ 
+ 
+-LIBSHARED=libmpdec.so.$PACKAGE_VERSION
++LIBSHARED=libmpdec.$PACKAGE_VERSION.dylib
+ 
+ 
+ # Language and compiler:

var/spack/repos/builtin/packages/cdecimal/package.py

@@ -0,0 +1,18 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Cdecimal(AutotoolsPackage):
+    """cdecimal is a fast drop-in replacement for the decimal module in
+    Python's standard library."""
+
+    homepage = "https://www.bytereef.org/mpdecimal/"
+    url      = "https://www.bytereef.org/software/mpdecimal/releases/cdecimal-2.3.tar.gz"
+
+    version('2.3', sha256='d737cbe43ed1f6ad9874fb86c3db1e9bbe20c0c750868fde5be3f379ade83d8b')
+
+    patch('darwin_install_name.patch', when='platform=darwin')

var/spack/repos/builtin/packages/libbsd/package.py

@@ -22,3 +22,6 @@ class Libbsd(AutotoolsPackage):
     version('0.8.6', sha256='467fbf9df1f49af11f7f686691057c8c0a7613ae5a870577bef9155de39f9687')
 
     patch('cdefs.h.patch', when='@0.8.6 %gcc@:4')
+
+    # https://gitlab.freedesktop.org/libbsd/libbsd/issues/1
+    conflicts('platform=darwin')

var/spack/repos/builtin/packages/libnsl/package.py

@@ -0,0 +1,29 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Libnsl(AutotoolsPackage):
+    """This library contains the public client interface for NIS(YP) and NIS+
+    in a IPv6 ready version."""
+
+    homepage = "https://github.com/thkukuk/libnsl"
+    url      = "https://github.com/thkukuk/libnsl/archive/v1.2.0.tar.gz"
+
+    version('1.2.0', sha256='a5a28ef17c4ca23a005a729257c959620b09f8c7f99d0edbfe2eb6b06bafd3f8')
+
+    depends_on('autoconf', type='build')
+    depends_on('automake', type='build')
+    depends_on('libtool',  type='build')
+    depends_on('m4',       type='build')
+    depends_on('pkgconfig@0.9.0:', type='build')
+    depends_on('gettext')
+    depends_on('rpcsvc-proto')
+    depends_on('libtirpc')
+
+    def autoreconf(self, spec, prefix):
+        autoreconf = which('autoreconf')
+        autoreconf('-fi')

var/spack/repos/builtin/packages/libtirpc/package.py

@@ -0,0 +1,22 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Libtirpc(AutotoolsPackage):
+    """Libtirpc is a port of Suns Transport-Independent RPC library to Linux.
+    """
+
+    homepage = "https://sourceforge.net/projects/libtirpc/"
+    url      = "https://sourceforge.net/projects/libtirpc/files/libtirpc/1.1.4/libtirpc-1.1.4.tar.bz2/download"
+
+    version('1.1.4', sha256='2ca529f02292e10c158562295a1ffd95d2ce8af97820e3534fe1b0e3aec7561d')
+
+    # FIXME: build error on macOS
+    # auth_none.c:81:9: error: unknown type name 'mutex_t'
+
+    def configure_args(self):
+        return ['--disable-gssapi']

var/spack/repos/builtin/packages/libxdmcp/package.py

@@ -17,4 +17,5 @@ class Libxdmcp(AutotoolsPackage):
     depends_on('xproto', type='build')
     depends_on('pkgconfig', type='build')
     depends_on('util-macros', type='build')
-    depends_on('libbsd')
+    depends_on('libbsd', when='platform=linux')
+    depends_on('libbsd', when='platform=cray')

var/spack/repos/builtin/packages/mpdecimal/package.py

@@ -0,0 +1,24 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Mpdecimal(AutotoolsPackage):
+    """mpdecimal is a package for correctly-rounded arbitrary precision
+    decimal floating point arithmetic."""
+
+    homepage = "https://www.bytereef.org/mpdecimal/"
+    url      = "https://www.bytereef.org/software/mpdecimal/releases/mpdecimal-2.4.2.tar.gz"
+    list_url = "https://www.bytereef.org/mpdecimal/download.html"
+
+    version('2.4.2', sha256='83c628b90f009470981cf084c5418329c88b19835d8af3691b930afccb7d79c7')
+
+    depends_on('gmake', type='build')
+
+    @property
+    def libs(self):
+        # Suffix is .so, even on macOS
+        return LibraryList(find(self.prefix.lib, 'libmpdec.so'))

var/spack/repos/builtin/packages/py-pymol/package.py

@@ -17,7 +17,7 @@ class PyPymol(PythonPackage):
 
     version('2.1.0', 'ef2ab2ce11d65785ca3258b4e6982dfb')
 
-    depends_on('python+tk', type=('build', 'run'))
+    depends_on('python+tkinter', type=('build', 'run'))
     depends_on('tcl')
     depends_on('tk')
     depends_on('py-pmw')

var/spack/repos/builtin/packages/python/ncurses.patch

@@ -1,11 +0,0 @@
---- a/setup.py	2016-08-30 15:39:59.334926574 -0500
-+++ b/setup.py	2016-08-30 15:46:57.227946339 -0500
-@@ -745,8 +745,6 @@
-         # use the same library for the readline and curses modules.
-         if 'curses' in readline_termcap_library:
-             curses_library = readline_termcap_library
--        elif self.compiler.find_library_file(lib_dirs, 'ncursesw'):
--            curses_library = 'ncursesw'
-         elif self.compiler.find_library_file(lib_dirs, 'ncurses'):
-             curses_library = 'ncurses'
-         elif self.compiler.find_library_file(lib_dirs, 'curses'):

var/spack/repos/builtin/packages/python/package.py

@@ -24,8 +24,8 @@
 class Python(AutotoolsPackage):
     """The Python programming language."""
 
-    homepage = "http://www.python.org"
+    homepage = "https://www.python.org/"
-    url = "http://www.python.org/ftp/python/2.7.8/Python-2.7.8.tgz"
+    url      = "https://www.python.org/ftp/python/3.7.2/Python-3.7.2.tgz"
     list_url = "https://www.python.org/downloads/"
     list_depth = 1
 
@@ -63,9 +63,6 @@ class Python(AutotoolsPackage):
     # See http://bugs.python.org/issue29846
     variant('shared', default=sys.platform != 'darwin',
             description='Enable shared libraries')
-    variant('tk', default=False, description='Provide support for Tkinter')
-    variant('ucs4', default=False,
-            description='Enable UCS4 (wide) unicode strings')
     # From https://docs.python.org/2/c-api/unicode.html: Python's default
     # builds use a 16-bit type for Py_UNICODE and store Unicode values
     # internally as UCS2. It is also possible to build a UCS4 version of Python
@@ -73,10 +70,10 @@ class Python(AutotoolsPackage):
     # builds then use a 32-bit type for Py_UNICODE and store Unicode data
     # internally as UCS4. Note that UCS2 and UCS4 Python builds are not binary
     # compatible.
+    variant('ucs4', default=False,
+            description='Enable UCS4 (wide) unicode strings')
     variant('pic', default=True,
             description='Produce position-independent code (for shared libs)')
-
-    variant('dbm', default=True, description='Provide support for dbm')
     variant(
         'optimizations',
         default=False,
@@ -87,31 +84,49 @@ class Python(AutotoolsPackage):
             description="Symlink 'python3' executable to 'python' "
             "(not PEP 394 compliant)")
 
-    depends_on("pkgconfig", type="build")
+    # Optional Python modules
-    depends_on("openssl")
+    variant('readline', default=True,  description='Build readline module')
-    depends_on("bzip2")
+    variant('ssl',      default=True,  description='Build ssl module')
-    depends_on("readline")
+    variant('sqlite3',  default=True,  description='Build sqlite3 module')
-    depends_on("ncurses")
+    variant('dbm',      default=True,  description='Build dbm module')
-    depends_on("sqlite")
+    variant('nis',      default=False, description='Build nis module')
-    depends_on("zlib")
+    variant('zlib',     default=True,  description='Build zlib module')
-    depends_on("tk", when="+tk")
+    variant('bz2',      default=True,  description='Build bz2 module')
-    depends_on("tcl", when="+tk")
+    variant('lzma',     default=True,  description='Build lzma module')
-    depends_on("gdbm", when='+dbm')
+    variant('pyexpat',  default=True,  description='Build pyexpat module')
+    variant('ctypes',   default=True,  description='Build ctypes module')
+    variant('tkinter',  default=False, description='Build tkinter module')
+    variant('uuid',     default=False, description='Build uuid module')
 
-    # https://docs.python.org/3/whatsnew/3.7.html#build-changes
+    depends_on('pkgconfig@0.9.0:', type='build')
-    depends_on("libffi", when="@3.7:")
-    depends_on("openssl@1.0.2:", when="@3.7:")
 
-    # Patch does not work for Python 3.1
+    # Optional dependencies
-    patch('ncurses.patch', when='@:2.8,3.2:')
+    # See detect_modules() in setup.py for details
+    depends_on('readline', when='+readline')
+    depends_on('ncurses', when='+readline')
+    depends_on('openssl', when='+ssl')
+    depends_on('openssl@1.0.2:', when='@3.7:+ssl')  # https://docs.python.org/3/whatsnew/3.7.html#build-changes
+    depends_on('sqlite@3.0.8:', when='+sqlite3')
+    depends_on('gdbm', when='+dbm')  # alternatively ndbm or berkeley-db
+    depends_on('libnsl', when='+nis')
+    depends_on('zlib@1.1.3:', when='+zlib')
+    depends_on('bzip2', when='+bz2')
+    depends_on('xz', when='@3.3:+lzma')
+    depends_on('expat', when='+pyexpat')
+    depends_on('libffi', when='+ctypes')
+    depends_on('tk', when='+tkinter')
+    depends_on('tcl', when='+tkinter')
+    depends_on('libuuid', when='+uuid')
+
+    patch('tkinter.patch', when='@:2.8,3.3: platform=darwin')
 
     # Ensure that distutils chooses correct compiler option for RPATH on cray:
-    patch('cray-rpath-2.3.patch', when="@2.3:3.0.1 platform=cray")
+    patch('cray-rpath-2.3.patch', when='@2.3:3.0.1 platform=cray')
-    patch('cray-rpath-3.1.patch', when="@3.1:3.99  platform=cray")
+    patch('cray-rpath-3.1.patch', when='@3.1:3.99  platform=cray')
 
     # Fixes an alignment problem with more aggressive optimization in gcc8
     # https://github.com/python/cpython/commit/0b91f8a668201fc58fa732b8acc496caedfdbae0
-    patch('gcc-8-2.7.14.patch', when="@2.7.14 %gcc@8:")
+    patch('gcc-8-2.7.14.patch', when='@2.7.14 %gcc@8:')
 
     # For more information refer to this bug report:
     # https://bugs.python.org/issue29712
@@ -156,37 +171,33 @@ def setup_environment(self, spack_env, run_env):
 
     def configure_args(self):
         spec = self.spec
+        config_args = []
 
         # setup.py needs to be able to read the CPPFLAGS and LDFLAGS
         # as it scans for the library and headers to build
         link_deps = spec.dependencies('link')
 
-        # Header files are often included assuming they reside in a
+        if link_deps:
-        # subdirectory of prefix.include, e.g. #include <openssl/ssl.h>,
+            # Header files are often included assuming they reside in a
-        # which is why we don't use HeaderList here. The header files of
+            # subdirectory of prefix.include, e.g. #include <openssl/ssl.h>,
-        # libffi reside in prefix.lib but the configure script of Python
+            # which is why we don't use HeaderList here. The header files of
-        # finds them using pkg-config.
+            # libffi reside in prefix.lib but the configure script of Python
-        cppflags = '-I' + ' -I'.join(dep.prefix.include
+            # finds them using pkg-config.
-                                     for dep in link_deps
+            cppflags = ' '.join('-I' + spec[dep.name].prefix.include
-                                     if dep.name != 'libffi')
+                                for dep in link_deps)
 
-        # Currently, the only way to get SpecBuildInterface wrappers of the
+            # Currently, the only way to get SpecBuildInterface wrappers of the
-        # dependencies (which we need to get their 'libs') is to get them
+            # dependencies (which we need to get their 'libs') is to get them
-        # using spec.__getitem__.
+            # using spec.__getitem__.
-        ldflags = ' '.join(spec[dep.name].libs.search_flags
+            ldflags = ' '.join(spec[dep.name].libs.search_flags
-                           for dep in link_deps)
+                               for dep in link_deps)
 
-        config_args = ['CPPFLAGS=' + cppflags, 'LDFLAGS=' + ldflags]
+            config_args.extend(['CPPFLAGS=' + cppflags, 'LDFLAGS=' + ldflags])
 
         # https://docs.python.org/3/whatsnew/3.7.html#build-changes
         if spec.satisfies('@:3.6'):
             config_args.append('--with-threads')
 
-        if '^libffi' in spec:
-            config_args.append('--with-system-ffi')
-        else:
-            config_args.append('--without-system-ffi')
-
         if spec.satisfies('@2.7.13:2.8,3.5.3:', strict=True) \
                 and '+optimizations' in spec:
             config_args.append('--enable-optimizations')
@@ -209,7 +220,7 @@ def configure_args(self):
             elif spec.satisfies('@3.0:3.2'):
                 config_args.append('--with-wide-unicode')
             elif spec.satisfies('@3.3:'):
-                # https://docs.python.org/3.3/whatsnew/3.3.html
+                # https://docs.python.org/3.3/whatsnew/3.3.html#functionality
                 raise ValueError(
                     '+ucs4 variant not compatible with Python 3.3 and beyond')
 
@@ -219,6 +230,35 @@ def configure_args(self):
         if '+pic' in spec:
             config_args.append('CFLAGS={0}'.format(self.compiler.pic_flag))
 
+        if spec.satisfies('@3.7:'):
+            if '+ssl' in spec:
+                config_args.append('--with-openssl={0}'.format(
+                    spec['openssl'].prefix))
+
+        if '+dbm' in spec:
+            # Default order is ndbm:gdbm:bdb
+            config_args.append('--with-dbmliborder=gdbm:bdb:ndbm')
+        else:
+            config_args.append('--with-dbmliborder=')
+
+        if '+pyexpat' in spec:
+            config_args.append('--with-system-expat')
+        else:
+            config_args.append('--without-system-expat')
+
+        if '+ctypes' in spec:
+            config_args.append('--with-system-ffi')
+        else:
+            config_args.append('--without-system-ffi')
+
+        if '+tkinter' in spec:
+            config_args.extend([
+                '--with-tcltk-includes=-I{0} -I{1}'.format(
+                    spec['tcl'].prefix.include, spec['tk'].prefix.include),
+                '--with-tcltk-libs={0} {1}'.format(
+                    spec['tcl'].libs.ld_flags, spec['tk'].libs.ld_flags)
+            ])
+
         return config_args
 
     @run_after('install')
@@ -260,26 +300,75 @@ def post_install(self):
             os.symlink(os.path.join(prefix.bin, 'python3-config'),
                        os.path.join(prefix.bin, 'python-config'))
 
-    # TODO: Once better testing support is integrated, add the following tests
+    @run_after('install')
-    # https://wiki.python.org/moin/TkInter
+    @on_package_attributes(run_tests=True)
-    #
+    def import_tests(self):
-    # Note: Only works if ForwardX11Trusted is enabled, i.e. `ssh -Y`
+        """Test that basic Python functionality works."""
-    #
+
-    #    if '+tk' in spec:
+        spec = self.spec
-    #        env['TK_LIBRARY']  = join_path(spec['tk'].prefix.lib,
+
-    #            'tk{0}'.format(spec['tk'].version.up_to(2)))
+        with working_dir('spack-test', create=True):
-    #        env['TCL_LIBRARY'] = join_path(spec['tcl'].prefix.lib,
+            # Ensure that readline module works
-    #            'tcl{0}'.format(spec['tcl'].version.up_to(2)))
+            if '+readline' in spec:
-    #
+                self.command('-c', 'import readline')
-    #        $ python
+
-    #        >>> import _tkinter
+            # Ensure that ssl module works
-    #
+            if '+ssl' in spec:
-    #        if spec.satisfies('@3:')
+                self.command('-c', 'import ssl')
-    #            >>> import tkinter
+                self.command('-c', 'import hashlib')
-    #            >>> tkinter._test()
+
-    #        else:
+            # Ensure that sqlite3 module works
-    #            >>> import Tkinter
+            if '+sqlite3' in spec:
-    #            >>> Tkinter._test()
+                self.command('-c', 'import sqlite3')
+
+            # Ensure that dbm module works
+            if '+dbm' in spec:
+                self.command('-c', 'import dbm')
+
+            # Ensure that nis module works
+            if '+nis' in spec:
+                self.command('-c', 'import nis')
+
+            # Ensure that zlib module works
+            if '+zlib' in spec:
+                self.command('-c', 'import zlib')
+
+            # Ensure that bz2 module works
+            if '+bz2' in spec:
+                self.command('-c', 'import bz2')
+
+            # Ensure that lzma module works
+            if spec.satisfies('@3.3:'):
+                if '+lzma' in spec:
+                    self.command('-c', 'import lzma')
+
+            # Ensure that pyexpat module works
+            if '+pyexpat' in spec:
+                self.command('-c', 'import xml.parsers.expat')
+                self.command('-c', 'import xml.etree.ElementTree')
+
+            # Ensure that ctypes module works
+            if '+ctypes' in spec:
+                self.command('-c', 'import ctypes')
+
+            # Ensure that tkinter module works
+            # https://wiki.python.org/moin/TkInter
+            if '+tkinter' in spec:
+                # Only works if ForwardX11Trusted is enabled, i.e. `ssh -Y`
+                if 'DISPLAY' in env:
+                    if spec.satisfies('@3:'):
+                        self.command('-c', 'import tkinter; tkinter._test()')
+                    else:
+                        self.command('-c', 'import Tkinter; Tkinter._test()')
+                else:
+                    if spec.satisfies('@3:'):
+                        self.command('-c', 'import tkinter')
+                    else:
+                        self.command('-c', 'import Tkinter')
+
+            # Ensure that uuid module works
+            if '+uuid' in spec:
+                self.command('-c', 'import uuid')
 
     def _save_distutil_vars(self, prefix):
         """

var/spack/repos/builtin/packages/python/tkinter.patch

@@ -0,0 +1,17 @@
+diff -Naur a/setup.py b/setup.py
+--- a/setup.py	2019-01-13 18:59:14.000000000 -0600
++++ b/setup.py	2019-01-13 19:00:31.000000000 -0600
+@@ -1787,13 +1787,6 @@
+         if self.detect_tkinter_explicitly():
+             return
+ 
+-        # Rather than complicate the code below, detecting and building
+-        # AquaTk is a separate method. Only one Tkinter will be built on
+-        # Darwin - either AquaTk, if it is found, or X11 based Tk.
+-        if (host_platform == 'darwin' and
+-            self.detect_tkinter_darwin(inc_dirs, lib_dirs)):
+-            return
+-
+         # Assume we haven't found any of the libraries or include files
+         # The versions with dots are used on Unix, and the versions without
+         # dots on Windows, for detection by cygwin.

var/spack/repos/builtin/packages/rpcsvc-proto/package.py

@@ -0,0 +1,20 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class RpcsvcProto(AutotoolsPackage):
+    """rpcsvc protocol definitions from glibc."""
+
+    homepage = "https://github.com/thkukuk/rpcsvc-proto"
+    url      = "https://github.com/thkukuk/rpcsvc-proto/releases/download/v1.4/rpcsvc-proto-1.4.tar.gz"
+
+    version('1.4', sha256='867e46767812784d8dda6d8d931d6fabb30168abb02d87a2a205be6d5a2934a7')
+
+    depends_on('gettext')
+
+    def configure_args(self):
+        return ['LIBS=-lintl']

var/spack/repos/builtin/packages/tcl/package.py

@@ -33,11 +33,6 @@ class Tcl(AutotoolsPackage):
 
     configure_directory = 'unix'
 
-    def setup_environment(self, spack_env, run_env):
-        # When using Tkinter from within spack provided python+tk, python
-        # will not be able to find Tcl/Tk unless TCL_LIBRARY is set.
-        run_env.set('TCL_LIBRARY', join_path(self.prefix, self.tcl_lib_dir))
-
     def install(self, spec, prefix):
         with working_dir(self.build_directory):
             make('install')
@@ -77,7 +72,8 @@ def symlink_tclsh(self):
 
     @property
     def libs(self):
-        return LibraryList([])
+        return find_libraries(['libtcl{0}'.format(self.version.up_to(2))],
+                              root=self.prefix, recursive=True)
 
     @property
     def command(self):
@@ -101,11 +97,18 @@ def tcl_builtin_lib_dir(self):
         return join_path(self.tcl_lib_dir,
                          'tcl{0}'.format(self.version.up_to(2)))
 
+    def setup_environment(self, spack_env, run_env):
+        # When using Tkinter from within spack provided python+tkinter, python
+        # will not be able to find Tcl/Tk unless TCL_LIBRARY is set.
+        run_env.set('TCL_LIBRARY', join_path(self.prefix, self.tcl_lib_dir))
+
     def setup_dependent_environment(self, spack_env, run_env, dependent_spec):
         """Set TCLLIBPATH to include the tcl-shipped directory for
         extensions and any other tcl extension it depends on.
         For further info see: https://wiki.tcl.tk/1787"""
 
+        spack_env.set('TCL_LIBRARY', join_path(self.prefix, self.tcl_lib_dir))
+
         # If we set TCLLIBPATH, we must also ensure that the corresponding
         # tcl is found in the build environment. This to prevent cases
         # where a system provided tcl is run against the standard libraries

var/spack/repos/builtin/packages/tk/package.py

@@ -30,14 +30,19 @@ class Tk(AutotoolsPackage):
 
     @property
     def libs(self):
-        return LibraryList([])
+        return find_libraries(['libtk{0}'.format(self.version.up_to(2))],
+                              root=self.prefix, recursive=True)
 
     def setup_environment(self, spack_env, run_env):
-        # When using Tkinter from within spack provided python+tk, python
+        # When using Tkinter from within spack provided python+tkinter, python
         # will not be able to find Tcl/Tk unless TK_LIBRARY is set.
         run_env.set('TK_LIBRARY', join_path(self.prefix.lib, 'tk{0}'.format(
             self.spec.version.up_to(2))))
 
+    def setup_dependent_environment(self, spack_env, run_env, dependent_spec):
+        spack_env.set('TK_LIBRARY', join_path(self.prefix.lib, 'tk{0}'.format(
+            self.spec.version.up_to(2))))
+
     def configure_args(self):
         spec = self.spec
         return ['--with-tcl={0}'.format(spec['tcl'].prefix.lib)]

var/spack/repos/builtin/packages/xz/package.py

@@ -20,3 +20,7 @@ class Xz(AutotoolsPackage):
     version('5.2.3', '1592e7ca3eece099b03b35f4d9179e7c')
     version('5.2.2', 'f90c9a0c8b259aee2234c4e0d7fd70af')
     version('5.2.0', '867cc8611760240ebf3440bd6e170bb9')
+
+    @property
+    def libs(self):
+        return find_libraries(['liblzma'], root=self.prefix, recursive=True)