</syntaxhighlight>
=== Q: Buffer
IO I/O Error
for uSD when accessing USB devices ===When
you try trying to write a large file on a
USB device (e.g. micro SD, connected to the
VM MVM through an adapter
) user may experience some ''Buffer I/O errors'' (followed by additional kernel errors,
like the one shown in depending on the
image, it can happen specific operation that
caused the
system crashes. [[File:Generic-card-reader.jpg|center|thumb|Generic Card Reader]] In case of error
, ) like the following (use <code>dmesg</code> on a terminal to see the kernel
message that is printed is the following log buffer) <pre class="mw-collapsible mw-collapsed">
[ 358.392710] sdb: sdb1 sdb2
[ 880.588382] EXT4-fs (sdb2): mounting ext3 file system using the ext4 subsystem
</pre>
To avoid this The root cause of the problemmay vary (e.g. Windows host OS device drivers, host hardware issue, Virtual Box incompatibility with host OS and so on) but, it in our experience, this is recommended caused by poor USB device or SD card reader. For this reason, as first action we suggest to change SD card adapter with a more robust one E.g. we've found that simple adapters like the one in the micro following picture, most of the time shows this kind of error during the creation of bootable SD card (like the one described in [[DESK-MX8M-L/Development/How to create a bootable microSD card|this article]]) [[File:Generic-card-reader.jpg|none|thumb]] === Q: OE Sanity check failed with <code>Fetcher failure for URL: '<nowiki>https://eula-downloads.yoctoproject.org/index.php'</nowiki></code> ===This usually happens from 1st October 2023 on Ubuntu 14.04 and Ubuntu 16.04 based MVM and the root cause is the DST Root CA X3 certificate expiration (see for example [https://superuser.com/questions/1679204/curl-on-ubuntu-14-all-lets-encrypt-certificates-are-expired-error-60 this superuser thread]) Without involving bitbake and Yocto, this can be easily reproduced with a <code>curl</code> command, and then choose here showed with it's error output:<syntaxhighlight lang="text">bash# curl https://eula-downloads.yoctoproject.org/index.php curl: (60) SSL certificate problem: certificate has expiredMore details here: http://curl.haxx.se/docs/sslcerts.html curl performs SSL certificate verification by default, using a "bundle" of Certificate Authority (CA) public keys (CA certs). If the default bundle file isn't adequate, you can specify an alternate file using the --cacert option.If this HTTPS server uses a certificate signed by a CA represented in the bundle, the certificate verification probably failed due to a problem with the certificate (it might be expired, or the name might not match the domain name in the URL).If you'd like to turn off curl's verification of the certificate, use the -k (or --insecure) option.</syntaxhighlight> The easy way to fix this is to disable the expired certificate the the following command (please note that it must be run with <code>sudo</code>)<syntaxhighlight lang="bash">sudo sed -i '/^mozilla\/DST_Root_CA_X3.crt$/ s/^/!/' /etc/ca-certificates.conf && sudo update-ca-certificates</syntaxhighlight> This is a more robust onepersistent change on the MVM, so you'll need to perform it only once After applying the fix, the <code>curl</code> command now succeed<syntaxhighlight lang="text">bash# curl https://eula-downloads.yoctoproject.org/index.php<html><head><title>301 Moved Permanently</title></head><body bgcolor="white"><center><h1>301 Moved Permanently</h1></center><hr><center>nginx/1.14.2</center></body></html></syntaxhighlight>