In order to prevent rate-limiting behavior by the Library of Congress
encountered when validating thousands of EADs, the validation command
uses a modified EAD 2002 schema that references an xlink.xsd file
hosted by NYU DLTS.
Therefore, the EAD validation functionality requires that the following
URL is online: http://dlts-support-files.s3.amazonaws.com/findingaids/xsd/xlink.xsd
The EAD 2002 schema is included in the executable using the
Golang Embedded FS functionality. Unfortunately, I (jgpawletko) was unable
to figure out a way to embed the xlink.xsd schema as well. I think this is
because the libxml2 C code performs the validation, and does not have direct
access to the file system embedded in the executable.
Going forward, the tradeoffs between a single-file deployment that requires that
the xlink.xsd URL is available vs. a multi-file deployment where the schema files
are deployed to the filesystem should be re-evaluated.
The Golang XML parser does not respect the order of elements encountered in the EAD files.
This is a known issue:
Mapping between XML elements and data structures is inherently flawed:
an XML element is an order-dependent collection of anonymous values,
while a data structure is an order-independent collection of named values.
...
To preserve order when it was important, selective stream parsing was implemented.
Please see here for the implementation.