Absolute URLs in Rails tests can be treated as external because the host is unknown, breaking redirect handling in Webrat. Use path-only matching or reset Webrat to the local site.

Timecop 0.3.4 and earlier can create records with timestamps in the past after Timecop.freeze; upgrading to 0.3.5 avoids the bug.

Time#utc, Time#gmt and Time#localtime mutate the receiver instead of returning a converted copy, which can cause hidden side effects in shared Time objects.

RGB-to-CMYK PDF conversion usually changes colors because no exact mapping exists; Ghostscript can rewrite the file with CMYK output on Ubuntu Linux.

Incorrectly oriented PDF pages can be fixed on Ubuntu with pdftk by applying page rotation during output generation.

tail -f can fail with “no space left on device” when Linux inotify watches are exhausted, often by daemons like Dropbox. Raising fs.inotify.max_user_watches restores file following.

Jenkins build failures trigger an automatic foam missile counter-attack aimed at the developer who broke the build.

Firefox regression can break Selenium tests after an upgrade; running an older browser is unsupported and may leave the system unstable.

Freezing Firefox versions for broken Selenium tests is a poor long-term fix because old releases stop receiving security patches. Auto-update can be disabled via about:config, but keeping Firefox current is safer.

before_validation returning false can make an ActiveRecord object invalid without populating errors, leaving validation failures hard to diagnose.

Rails’ distance_of_time_in_words can be too imprecise when a fixed unit is needed. A custom helper returns rounded differences in days, months, or years.

Convert a large PDF into tiled pages for printing as a poster using pdfposter; sizing the output can be awkward, but it works for oversized prints.

Repository navigation becomes faster with GitHub’s file-name search shortcut, letting you jump to files immediately instead of scrolling through folders.

Handy ActiveSupport helpers add callbacks, message signing and encryption, ordered options, array wrapping, deep hash merging, whitespace squishing, and zone-aware current time.

Single inline controls like checkboxes or images can sit top-aligned inside a line-height container when they are alone; adding adjacent inline content or a non-breaking space centers them.

Ruby-GetText may execute entire files while scanning for ActiveRecord models, so one-off scripts can run during PO rebuilds.

MySQL database directories can misrepresent real storage use when ibdata1 holds the data; querying information_schema.TABLES reveals per-database size in MB.

grep -c counts matching lines, not repeated hits on the same line. Inserting line breaks with sed makes every occurrence count.

Solarized support in RubyMine requires importing an IntelliJ port, and selecting a scheme can reset the editor font.

FreeBSD systems can fail to get network access even when rc.conf enables DHCP. Starting dhclient manually or rebooting can restore connectivity.

Sublime Text 2 font appearance can be customized through user settings, including typeface and size, with changes applied immediately after saving.

Samsung TVs used as monitors can have audio routing problems, input lag, and oversharp text, and store settings only after leaving store-demo mode.

Software RAID on Amazon EC2 EBS volumes improves I/O for database and other intensive workloads. mdadm creates the array and preserves it across reboots.