build: no required environment variables
R=adg, r, PeterGo
CC=golang-dev
https://golang.org/cl/1942044
diff --git a/doc/install.html b/doc/install.html
index 2c1ff21..601edc5 100644
--- a/doc/install.html
+++ b/doc/install.html
@@ -20,15 +20,35 @@
<h2>Environment variables</h2>
<p>
-The Go compilation environment depends on three environment variables plus one optional variable:
+The Go compilation environment can be customized by five environment variables.
+None are required by the build, but you may wish to set them
+to override the defaults.
</p>
<dl>
<dt>
<code>$GOROOT</code>
</dt>
-<dd>The root of the Go tree. Typically this is <code>$HOME/go</code>
- but it can be any directory.
+<dd>
+ The root of the Go tree, often <code>$HOME/go</code>.
+ This defaults to the parent of the directory where <code>all.bash</code> is run.
+ Although this variable is optional, the examples and typescripts below
+ use it as shorthand for the location where you installed Go.
+ If you choose not to set <code>$GOROOT</code>, you must
+ run <code>gomake</code> instead of <code>make</code> or <code>gmake</code>
+ when developing Go programs using the conventional makefiles.
+</dd>
+
+<dt>
+ <code>$GOROOT_FINAL</code>
+</dt>
+<dd>
+ The value assumed by installed binaries and scripts when
+ <code>$GOROOT</code> is not set.
+ It defaults to the value used for <code>$GOROOT</code>.
+ If you want to build the Go tree in one location
+ but move it elsewhere after the build, set
+ <code>$GOROOT_FINAL</code> to the eventual location.
</dd>
<dt>
@@ -36,6 +56,10 @@
</dt>
<dd>
The name of the target operating system and compilation architecture.
+ These default to the local system's operating system and
+ architecture.
+
+ <p>
Choices for <code>$GOOS</code> are <code>linux</code>,
<code>freebsd</code>,
<code>darwin</code> (Mac OS X 10.5 or 10.6),
@@ -74,11 +98,10 @@
<td></td><td><code>nacl</code></td> <td><code>386</code></td>
</tr>
</table>
- <p>
</dd>
<dt>
-<code>$GOBIN</code> (optional)
+<code>$GOBIN</code>
</dt>
<dd>
The location where binaries will be installed.
@@ -88,7 +111,7 @@
</dd>
<dt>
-<code>$GOARM</code> (optional, arm, default=6)
+<code>$GOARM</code> (arm, default=6)
</dt>
<dd>
The ARM architecture version the runtime libraries should target.
@@ -103,18 +126,24 @@
Note that <code>$GOARCH</code> and <code>$GOOS</code> identify the
<em>target</em> environment, not the environment you are running on.
In effect, you are always cross-compiling.
+By architecture, we mean the kind of binaries
+that the target environment can run:
+an x86-64 system running a 32-bit-only operating system
+must set <code>GOARCH</code> to <code>386</code>,
+not <code>amd64</code>.
</p>
<p>
-Set these variables in your shell profile (<code>$HOME/.bashrc</code>,
+If you choose to override the defaults,
+set these variables in your shell profile (<code>$HOME/.bashrc</code>,
<code>$HOME/.profile</code>, or equivalent). The settings might look
something like this:
</p>
<pre>
export GOROOT=$HOME/go
-export GOARCH=amd64
-export GOOS=linux
+export GOARCH=amd64 # optional
+export GOOS=linux # optional
</pre>
<p>
@@ -224,16 +253,21 @@
</pre>
<p>
-If all goes well, it will finish by printing
+If all goes well, it will finish by printing output like:
</p>
<pre>
--- cd ../test
N known bugs; 0 unexpected bugs
+
+---
+Installed Go for darwin/amd64 in /Users/you/go; the compiler is 6g.
</pre>
<p>
-where <var>N</var> is a number that varies from release to release.
+where <var>N</var> is a number that varies from release to release
+and the details on the last line will reflect the operating system,
+architecture, and root directory used during the install.
</p>
<h2>Writing programs</h2>
