Use $<attr>Path instead of $<attr> for passAsFile

This commit is contained in:
Eelco Dolstra 2015-02-17 16:42:54 +01:00
parent a70d275f3d
commit bd91064150
3 changed files with 13 additions and 7 deletions

View file

@ -254,11 +254,17 @@ big = "a very long string";
</programlisting>
then when the builder runs, the environment variable
<envar>big</envar> will contain the absolute path to a temporary
file containing <literal>a very long string</literal>. This is
useful when you need to pass large strings to a builder, since
most operating systems impose a limit on the size of the
environment (typically, a few hundred kilobyte).</para></listitem>
<envar>bigPath</envar> will contain the absolute path to a
temporary file containing <literal>a very long
string</literal>. That is, for any attribute
<replaceable>x</replaceable> listed in
<varname>passAsFile</varname>, Nix will pass an environment
variable <envar><replaceable>x</replaceable>Path</envar> holding
the path of the file containing the value of attribute
<replaceable>x</replaceable>. This is useful when you need to pass
large strings to a builder, since most operating systems impose a
limit on the size of the environment (typically, a few hundred
kilobyte).</para></listitem>
</varlistentry>

View file

@ -1662,7 +1662,7 @@ void DerivationGoal::startBuilder()
} else {
Path p = tmpDir + "/.attr-" + int2String(fileNr++);
writeFile(p, i.second);
env[i.first] = p;
env[i.first + "Path"] = p;
}
}

View file

@ -10,7 +10,7 @@ mkDerivation {
passAsFile = [ \"foo\" ];
foo = [ \"xyzzy\" ];
builder = builtins.toFile \"builder.sh\" ''
[ \"\$(cat \$foo)\" = xyzzy ]
[ \"\$(cat \$fooPath)\" = xyzzy ]
touch \$out
'';
}