In my first decade writing Makefiles, I developed the bad habit of liberally using GNU Make’s extensions. I didn’t know the line between GNU Make and the portable features guaranteed by POSIX. Usually it didn’t matter much, but it would become an annoyance when building on non-Linux systems, such as on the various BSDs. I’d have to specifically install GNU Make, then remember to invoke it (i.e. as gmake) instead of the system’s make.

I’ve since become familiar and comfortable with make’s official specification, and I’ve spend the last year writing strictly portable Makefiles. Not only has are my builds now portable across all unix-like systems, my Makefiles are cleaner and more robust. Many of the common make extensions — conditionals in particular — lead to fragile, complicated Makefiles and are best avoided anyway. It’s important to be able to trust your build system to do its job correctly.

This tutorial should be suitable for make beginners who have never written their own Makefiles before, as well as experienced developers who want to learn how to write portable Makefiles.

Home cooking.

In the spring of 1958, after President Dwight Eisenhower called to create a civilian space agency, the US Air Force assumed it would lead any national spaceflight effort. As such, the service prepared a detailed, multi-stage plan called Man in Space with the goal of landing a man on the Moon by the mid 1960s.

In fiscal 2010, just before the March 2012 disaster at Tokyo Electric Power Company Holding’s Fukushima No. 1 nuclear power plant, the national average CO2 emission was 416 grams per kilowatt-hour. In fiscal 2013, after all nuclear power plants were idled, the figure rose to 570 grams.

Fuel economy is about 10 km per liter for gasoline-powered passenger cars and a little over 20 km per liter for hybrid cars. The comparable figure for EVs is some 10 km per kilowatt-hour. Even with all nuclear power plants idled, an EV emits only about half as much CO2 as hybrid vehicles. Even if all power stations used coal, the CO2 emission per kilowatt-hour would be 864 grams, making CO2 emissions from an EV less than from a hybrid car.

Slightly less walking today compared to yesterday.

Mediterranean. #nofilter

Good morning! #nofilter (at Hotel Eetu)

Ridiculously picturesque Catalan village. (at Monells, Cataluna, Spain)

The fact that any CA can issue a certificate for any domain name is commonly cited as the weakest aspect of the PKI ecosystem. Although CAs want to do the right thing, there are no technical controls that prevent them from doing whatever they chose to do. That’s why we say that the PKI ecosystem is a weak as the weakest link. With hundreds of CAs, there are potentially many weak links.

CAA creates a DNS mechanism that enables domain name owners to whitelist CAs that are allowed to issue certificates for their hostnames. It operates via a new DNS resource record (RR) called CAA (type 257). Owners can restrict certificate issuance by specifying zero or more CAs; if a CA is allowed to issue a certificate, their own hostname will be in the DNS record. For example, this is what someone’s CAA configuration could be (in the zone file):

example.org. CAA 128 issue "letsencrypt.org"

Most of the really wrong design decisions in the Shuttle system — the side-mounted orbiter, solid rocket boosters, lack of air-breathing engines, no escape system, fragile heat protection — were the direct fallout of this design phase, when tight budgets and onerous Air Force requirements forced engineers to improvise solutions to problems that had as much to do to do with the mechanics of Congressional funding as the mechanics of flight. In a pattern that would recur repeatedly in the years to come, NASA managers decided that they were better off making spending cuts on initial design even if they resulted in much higher operating costs over the lifetime of the program.

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