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			XML
		
	
	
	
	
	
			
		
		
	
	
			71 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
| <appendix><title>Troubleshooting</title>
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| 
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| <para>This section provides solutions for some common problems.</para>
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| 
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| 
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| <sect1><title>Berkeley DB: <quote>Cannot allocate memory</quote></title>
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| 
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| <para>Symptom: Nix operations (in particular the
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| <command>nix-store</command> operations <option>--gc</option>,
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| <option>--verify</option>, and <option>--clear-substitutes</option> —
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| the latter being called by <command>nix-channel --update</command>)
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| failing:
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| 
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| <screen>
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| $ nix-store --verify
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| error: Db::del: Cannot allocate memory</screen>
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| 
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| </para>
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| 
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| <para>Possible solution: make sure that no Nix processes are running,
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| then do:
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| 
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| <screen>
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| $ cd /nix/var/nix/db
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| $ rm __db.00*</screen>
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| 
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| </para>
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| 
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| </sect1>
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| 
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| 
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| <sect1><title>Collisions in <command>nix-env</command></title>
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| 
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| <para>Symptom: when installing or upgrading, you get an error message such as
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| 
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| <screen>
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| $ nix-env -i docbook-xml
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| ...
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| adding /nix/store/s5hyxgm62gk2...-docbook-xml-4.2
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| collission between `/nix/store/s5hyxgm62gk2...-docbook-xml-4.2/xml/dtd/docbook/calstblx.dtd'
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|   and `/nix/store/06h377hr4b33...-docbook-xml-4.3/xml/dtd/docbook/calstblx.dtd'
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|   at /nix/store/...-builder.pl line 62.</screen>
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| 
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| </para>
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| 
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| <para>The cause is that two installed packages in the user environment
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| have overlapping filenames (e.g.,
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| <filename>xml/dtd/docbook/calstblx.dtd</filename>.  This usually
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| happens when you accidentally try to install two versions of the same
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| package.  For instance, in the example above, the Nix Packages
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| collection contains two versions of <literal>docbook-xml</literal>, so
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| <command>nix-env -i</command> will try to install both.  The default
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| user environment builder has no way to way to resolve such conflicts,
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| so it just gives up.</para>
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| 
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| <para>Solution: remove one of the offending packages from the user
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| environment (if already installed) using <command>nix-env
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| -e</command>, or specify exactly which version should be installed
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| (e.g., <literal>nix-env -i docbook-xml-4.2</literal>).</para>
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| 
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| <para>Alternatively, you can modify the user environment builder
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| script (in
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| <filename><replaceable>prefix</replaceable>/share/nix/corepkgs/buildenv/builder.pl</filename>)
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| to implement some conflict resolution policy.  E.g., the script could
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| be modified to rename conflicting file names, or to pick one over the
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| other.</para>
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| 
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| </sect1>
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| 
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| 
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| </appendix>
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