rlucastemp

After having fixed the DBD::Pg bug resulting from the faulty Apple Security Update, which necessitated recompiling Postgres and running sudo ranlib /usr/local/pgsql/lib/libpq.a I discovered another bug.

My PostgreSQL was compiled with UTF-8 support, and my DBD::Pg was rebuilt/reinstalled after the Postgres recompile. However, my scripts were still bombing out with:


dyld: perl Undefined symbols:
_is_utf8_string
Trace/BPT trap


This posting speculates at the solution, which happily works:
http://www.geocrawler.com/mail/msg.php3?msg_id=10411736&list=105

Specifically, commenting out the code between the ifdefs in the section that refers to is_utf8_string (circa line 1482 of dbdimp.c), then make clean / make / make install allowed DBD::Pg 1.21 to install OK and stopped perl from crashing out with the above error.

Now, to see if that completely breaks something else…

OK, I have determined what blogs are for. They give an easy way to publish aggregated technical fix information in a search-engine-friendly format. Aggregated: quite often, fixing a specific technical problem (even a common one!) requires looking around the web at a number of false leads on mailing list archives, tech docs, knowledge bases, etc. Putting the whole solution, once found, into a single blog entry (including links / attribution to the original solvers) makes sense. Seach-engine-friendly: mailing list archives are good, but only if they get web-published and Googled. Realistically, if it’s not in Google, it doesn’t exist — especially in the realm of technical problems that could have any number of origins (imagine compiling an XML to Excel Perl module on Mac OS X: is your problem with GCC, libxml, Excel, Perl, or Mac OS X? Which mailing lists do you search first?). Additionally, most computer problems have a characteristic error message which appears with some limited amount of variation. That message is easy to post on a blog. I originally believed that the solution to the aggregated technical fix information was a search-engine feeder backed by an RDBMS, but it is clear that any schema will be too inflexible for the variety of problems. Better to post error messages verbatim, try to be as explicit about keywords as practicable (if it segfaults, include the words “crash’, “segmentation fault”, and “segfault” as an aid to searching), and let Google handle the hard stuff far better than a FTS through an RDBMS could hope. Why do this? Well, this is a case of the comedy of the commons: figuring out a solution like this on one’s own or by searching through mailing lists piecemeal could consume hours or days of productive time. However, posting a solution once found is trivial, taking mere minutes. If even one other person posts a solution that I find which saves me 3-4 hours, it’s worth all the time I’ll ever spend in posting such things.

For Mac OS X users who installed the Software Update with a security component on 24 March 2003, some things might be broken if you use Apache, Sendmail, or the Perl PostgreSQL module DBD::Pg.

—
1) Regarding Sendmail:

See http://www.macosxhints.com/article.php?story=20030306145838840

(relevant error message: Sendmail might complain in /var/log/mail.log of “Deferred: Connection refused by localhost “)

(summary: Apple makes sendmail look at /etc/mail/submit.cf instead of sendmail.cf)

—
2) Regarding Apache:

See http://ganter.dyndns.org/misc/apple_ssl.php and http://apple.slashdot.org/comments.pl?sid=58276&threshold=1&commentsort=0&tid=172&mode=thread&cid=5640470

(relevant error message: Apache segfaults out on some SSL requests with the crash message [try /var/log/system.log]

Exception: EXC_BAD_ACCESS (0x0001) Codes: KERN_INVALID_ADDRESS (0x0001)

… and specifically complains that the error is in ssl_var_lookup_ssl)

(summary: Apple supplies a faulty libssl.so for Apache; a working version is provided)

(fix: see dyndns link above or try http://cyber.law.harvard.edu/blogs/gems/rlucas/libssl.so NO WARRANTY courtesy only mirror)

—
3) Regarding DBD::Pg
See http://gborg.postgresql.org/pipermail/dbdpg-general/2003-March/000039.html

(relevant error message:

dyld: perl Undefined symbols:
_BIO_free
_BIO_new_mem_buf
_DH_check
_DH_generate_parameters
_DH_size
_ERR_get_error
_ERR_reason_error_string
_EVP_PKEY_free
_PEM_read_DHparams
_PEM_read_PrivateKey
_PEM_read_X509
_PEM_read_bio_DHparams
_SSL_CTX_ctrl
_SSL_CTX_free
_SSL_CTX_load_verify_locations
_SSL_CTX_new
_SSL_CTX_set_tmp_dh_callback
_SSL_CTX_set_verify
_SSL_CTX_set_verify_depth
_SSL_connect
_SSL_free

… and more, whenever a script uses DBD::Pg.)

(summary: Perl scripts now crash out. Might be because PostgreSQL was compiled before the security update. Does anyone know otherwise?)

—
I am going to install the July Security Update to see if it fixes things at all.

—
UPDATE: The July security update does not fix it. However, recompiling PostgreSQL fixes most of the errors (see 25 July 2003 entry for a persistent error with utf-8 support).

Previously, I made the following assertions about the way in which domain knowledge was spread on the Internet 10 years ago and is spread today:

– Previously, the locus of online production and retrieval of knowledge was a group (Usenet newsgroup). The effect of the Web (initially) was to shift that locus to an individual person, company, or organization.

– The old style of interaction was conversational and collaborative, exemplifying “peer-to-peer” before that buzzphrase came into common (over)use. The Web’s effect was to move the interaction to a largely client-server, publisher-reader type relationship.

– The “easy” knowledge problems have been solved pretty well (the easy ones are those that one can imagine a SQL query for, like “what time is the movie playing,” or “what score/price did my team/stock achieve?”). The “hard” problems are those that you can’t imagine a SQL query for, but you could get answers to if you were in a room with a bunch of knowledgable folks.

– New (uses of) technologies like blogs, Wikis, and Content Management Systems are helping to move us back up to the point we were at in 1993.

Hmm, how does this work?