copy debian dependencies over from InstallDetails

[Imported from Trac: page DownloadDebianPackages, version 16]

DownloadDebianPackages.md

@@ -121,12 +121,54 @@ refrain from running unit tests.
 Many of Tahoe's build dependencies can be satisfied by first installing
 certain debian packages, and the Tahoe build process will download and build
 many of the others. Please see source:docs/debian.txt for details about
-building Tahoe on a debian-based system.
+building Tahoe on a debian-based system. The following text is a copy of
+source:docs/debian.txt .
+
+The Tahoe build process will download and install many of its dependencies
+when you run `make` or `setup.py build`. The base set of
+functionality that it cannot build on its own are provided by the following
+debian packages, so you must have these installed before you will be able to
+do much of anything. (note that the authoritative list of packages is in the
+"`Build-Depends:`" clause of
+[misc/sid/debian/control]source:misc/sid/debian/control):
+
+ * build-essential (this includes gcc, g++, make, and the headers in libc-dev)
+ * debhelper
+ * cdbs
+ * python-central
+ * python-setuptools
+ * python
+ * python-dev
+
+In addition, to use the "`make deb-PLATFORM-head`" target, you will also
+need the "debchange" utility from the "devscripts" package, and the
+"fakeroot" package.
+
+To actually run a Tahoe node from a debian package, you will need the following
+supporting libraries installed. (again, the authoritative list of packages
+is in the `Depends:` clause of
+[misc/sid/debian/control]source:misc/sid/debian/control)
+
+ * python-twisted-core
+ * python-twisted-names
+ * python-foolscap
+ * python-pyopenssl
+ * python-nevow
+ * python-simplejson
+ * python-zfec
+ * python-pycryptopp
+
+Even if you don't intend to create a Tahoe .deb package, you can install the
+supporting libraries from debian packages to reduce the build-time
+download-and-compile work. The Tahoe build process will use any pre-installed
+libraries it can find, and will download+build everything else.
 
 ## Building a Debian Package
 
 Please see source:docs/debian.txt for details about building your own debian
-packages from a Tahoe source tree.
+packages from a Tahoe source tree. You will need to install the packages
+described above, including the "devscripts" and "fakeroot" packages, and you
+will use the `make deb-$PLATFORM-head` target.
 
 Note that this is entirely optional. Tahoe will run just fine from a source
 tree: creating a debian package is merely a convenience for sysadmins to help