Author: ken
Date: Sat Jan 26 18:38:43 2019
New Revision: 21044
Log:
Rust - strongly recommend using /opt, and explain why.
Modified:
trunk/BOOK/general/prog/rust.xml
trunk/BOOK/introduction/welcome/changelog.xml
Modified: trunk/BOOK/general/prog/rust.xml
==============================================================================
--- trunk/BOOK/general/prog/rust.xml Sat Jan 26 17:49:29 2019 (r21043)
+++ trunk/BOOK/general/prog/rust.xml Sat Jan 26 18:38:43 2019 (r21044)
@@ -73,19 +73,25 @@
<note>
<para>
- When you upgrade to a newer version, the new libraries will have
various
- hashes in their names and therefore there will be a mix of versions but
- only one of each will be usable. A binary distribution would use its
- package manager to delete all the old <application>rust</application>
- installation before updating. You may wish to do the same to save
space.
+ Although BLFS usually installs in <filename
+ class="directory">/usr</filename>, when you later upgrade to a newer
+ version of <application>rust</application> the old libraries in
<filename
+ class="directory">/usr/lib/rustlib</filename> will remain, with various
+ hashes in their names, but will not be usable and will waste space. The
+ editors recommend placing the files in the <filename
+ class="directory">/opt</filename> directory. In particular, if you
+ have reason to rebuild with a modified configuration (e.g. using the
+ shipped LLVM after building with shared LLVM, but perhaps also the
+ reverse situation) it it possible for the install to leave a broken
+ <command>cargo</command> program. In such a situation, either remove
+ the existing installation first, or use a different prefix such as
+ /opt/rustc-&rust-version;-build2.
</para>
<para>
- One alternative when working with multiple versions or just updating
- to a new version is to place the files in the
- <filename class="directory">/opt</filename> directory. The
instructions
- below provide optional commands to support better control of
- new package versions or reinstallation of the current version.
+ If you prefer, you can of course change the prefix to <filename
+ class="directory">/usr</filename> and omit the
+ <command>ldconfig</command> and the actions to add rustc to the PATH.
</para>
</note>
@@ -104,7 +110,7 @@
<para>
Rustc defaults to building for ALL supported architectures, using a
shipped copy of LLVM. In BLFS the build is only for the X86
architecture.
- If you intend to develop rust crates, this build may not be good
+ If you intend to develop rust crates, this build may not be good
enough for your purposes.
</para>
<para>
@@ -187,16 +193,16 @@
<title>Installation of Rust</title>
<para>
- If you are going to install into the
- <filename class="directory">/opt</filename> directory, remove
- conflicting entries and recreate the required entries.
+ To install into the
+ <filename class="directory">/opt</filename> directory, remove the symlink
+ and create a new directory (i.e. with a different name if trying a
+ modified build).
As the <systemitem class="username">root</systemitem>
user:
</para>
-<screen role="root"><userinput>rm -rf /opt/rustc /opt/rustc-&rust-version;
&&
-mkdir /opt/rustc-&rust-version; &&
-ln -sv rustc-&rust-version; /opt/rustc</userinput></screen>
+<screen role="root"><userinput>mkdir /opt/rustc-&rust-version;
&&
+ln -svfin rustc-&rust-version; /opt/rustc</userinput></screen>
<note>
<para>
@@ -339,6 +345,13 @@
<title>Command Explanations</title>
<para>
+ <command>ln -svfn rustc-&rust-version; /opt/rustc</command>: if this is
+ not the first use of the <filename
class="directory">/opt/rustc</filename>
+ symlink, overwrite it by forcing, and use the '-n' flag to avoid getting
+ confusing results from e.g. <command>ls -l</command>.
+ </para>
+
+ <para>
<command>targets = "X86"</command>: this avoids building all the
available
linux cross-compilers (Aarch64, MIPS, PowerPC, SystemZ, etc).
Unfortunately,
rust insists on installing source files for these below
Modified: trunk/BOOK/introduction/welcome/changelog.xml
==============================================================================
--- trunk/BOOK/introduction/welcome/changelog.xml Sat Jan 26 17:49:29
2019 (r21043)
+++ trunk/BOOK/introduction/welcome/changelog.xml Sat Jan 26 18:38:43
2019 (r21044)
@@ -45,6 +45,17 @@
<para>January 24th, 2019</para>
<itemizedlist>
<listitem>
+ <para>[ken] - For rust, strongly recommend installing in /opt - this
+ allows multiple versions to be used (fallback, testing a different
+ config, trying a newer version) by merely (re-)running ldconfig after
+ updating the symlink. It also prevents libraries from a previous
version
+ taking up space in /usr/lib/rustlib/ (previous /opt versions can
easily
+ be removed). Using a new prefix should also prevent the situation
where
+ changing the config.toml (e.g. from sys llvm to shipped llvm) builds
+ fine but leaves a broken installation because cargo can no longer
find
+ the matching versions of the libraries.</para>
+ </listitem>
+ <listitem>
<para>[ken] - Tweak the details of which rust tests might
fail.</para>
</listitem>
<listitem>
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