Works for me.
If I make the file test.xsl
:
<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<root>
<multins xmlns:abc="http://example.com/1" xmlns:def="http://example.com/2" />
</root>
</xsl:template>
</xsl:stylesheet>
And then run it
xsltproc test.xsl test.xsl
<?xml version="1.0"?>
<root><multins xmlns:abc="http://example.com/1" xmlns:def="http://example.com/2"/></root>
with this version info :
$ xsltproc --version
Using libxml 20703, libxslt 10124 and libexslt 813
xsltproc was compiled against libxml 20632, libxslt 10124 and libexslt 813
libxslt 10124 was compiled against libxml 20632
libexslt 813 was compiled against libxml 20632