/usr/include/gnucash/GNCId.h is in gnucash-common 1:2.6.1-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | #include "qof.h"
/* Equivalent function prototype:
* void xaccGUIDNew (GncGUID *guid, QofBook *book)
*/
#define xaccGUIDNew(guid,book) \
qof_instance_guid_new (qof_book_get_entity_table (book), (guid))
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