<blockquote>
<p>Uh, looks like you ran out of memory. Try again with <code>GNRC_NETIF_NUMOF=1</code>.<br>
Weird, my samr21 also just has 32k of RAM and I didn't have that problem.</p>
</blockquote>
<p>Just to be sure I added a print statement here and buf points to NULL:</p>
<div class="highlight highlight-source-c"><pre><span class="pl-c"><span class="pl-c">/*</span> just return length when buf == NULL <span class="pl-c">*/</span></span>
    <span class="pl-k">if</span> (buf == <span class="pl-c1">NULL</span>) {
        <span class="pl-c1">puts</span>(<span class="pl-s"><span class="pl-pds">"</span>hello-world<span class="pl-pds">"</span></span>);
        <span class="pl-k">goto</span> out;
    }</pre></div>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/RIOT-OS/RIOT/pull/12128?email_source=notifications&email_token=ABE7WYFOGIV6B5N2POLRMITQLYMYXA5CNFSM4ISOCPJ2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7ZEZGQ#issuecomment-535973018">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/ABE7WYABHQJLIHTGLGV7NFTQLYMYXANCNFSM4ISOCPJQ">mute the thread</a>.<img src="https://github.com/notifications/beacon/ABE7WYBH2OUW3P3AGTMQOATQLYMYXA5CNFSM4ISOCPJ2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7ZEZGQ.gif" height="1" width="1" alt="" /></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/RIOT-OS/RIOT/pull/12128?email_source=notifications\u0026email_token=ABE7WYFOGIV6B5N2POLRMITQLYMYXA5CNFSM4ISOCPJ2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7ZEZGQ#issuecomment-535973018",
"url": "https://github.com/RIOT-OS/RIOT/pull/12128?email_source=notifications\u0026email_token=ABE7WYFOGIV6B5N2POLRMITQLYMYXA5CNFSM4ISOCPJ2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7ZEZGQ#issuecomment-535973018",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>