build/pkgs{appdirs,distlib,filelock,virtualenv}/spkg-configure.m4: Ma…

…rk as not required if system tox is used

build/pkgs/appdirs/spkg-configure.m4

@@ -0,0 +1,7 @@
+SAGE_SPKG_CONFIGURE([appdirs], [
+    sage_spkg_install_appdirs=yes
+  ], [dnl REQUIRED-CHECK
+    AC_REQUIRE([SAGE_SPKG_CONFIGURE_VIRTUALENV])
+    dnl only needed as a dependency of virtualenv.
+    AS_VAR_SET([SPKG_REQUIRE], [$sage_spkg_install_virtualenv])
+  ])

build/pkgs/distlib/spkg-configure.m4

@@ -0,0 +1,7 @@
+SAGE_SPKG_CONFIGURE([distlib], [
+    AC_REQUIRE([SAGE_SPKG_CONFIGURE_VIRTUALENV])
+    sage_spkg_install_distlib=yes
+  ], [dnl REQUIRED-CHECK
+    dnl only needed as a dependency of virtualenv.
+    AS_VAR_SET([SPKG_REQUIRE], [$sage_spkg_install_virtualenv])
+  ])

build/pkgs/filelock/spkg-configure.m4

@@ -0,0 +1,9 @@
+SAGE_SPKG_CONFIGURE([filelock], [
+    sage_spkg_install_filelock=yes
+  ], [dnl REQUIRED-CHECK
+    AC_REQUIRE([SAGE_SPKG_CONFIGURE_VIRTUALENV])
+    AC_REQUIRE([SAGE_SPKG_CONFIGURE_TOX])
+    dnl only needed as a dependency of tox and virtualenv.
+    AS_IF([test $sage_spkg_install_virtualenv = no -a $sage_spkg_install_tox = no],
+          AS_VAR_SET([SPKG_REQUIRE], [no]))
+  ])

build/pkgs/virtualenv/spkg-configure.m4

@@ -0,0 +1,7 @@
+SAGE_SPKG_CONFIGURE([virtualenv], [
+    sage_spkg_install_virtualenv=yes
+  ], [dnl REQUIRED-CHECK
+    AC_REQUIRE([SAGE_SPKG_CONFIGURE_TOX])
+    dnl virtualenv is only needed when we cannot use system tox.
+    AS_VAR_SET([SPKG_REQUIRE], [$sage_spkg_install_tox])
+  ])