When I upgrade a package, homebrew prompts this:  ==&gt; Upgrading mysql@5.7 Warning: A newer Command Line Tools release is available. Update them from Software Update in System Preferences or https://developer.apple.com/download/more/.   I have XCode Version 11.3 (11C29) installed, and no updates in System Preferences or App Store      Opening Xcode does not prompt me to install command line tools either, how can I get the latest version?
Hello,    This question is about the Command Line Developer Tools that are usually installed with xcode-select --install and updated via a software update from the Mac App Store (at least until macOS 10.13). I use the developer toolchain on a daily basis and it has always worked and updated without issues.    Today I've updated my mac from High Sierra 10.13.6 to Mojave 10.14.1, and I've lost the ability to update the Developer Tools.    After the update I've executed a terminal command that relies on the developer tools being installed. It was a command to update , although I don't think that the specifics matter, as I believe that any task that tried to access the developer tools would have triggered the same error message.    The error was:   xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun       The phrasing was new (maybe), but I thought that it was caused by the usual need to re-install the Developer Tools after some macOS updates.    Later I tried to dig a bit deeper into the failure, and found out that:  $ ls -l /Library/Developer/CommandLineTools/usr/total 0drwxr-xr-x  3 root  admin  96  4 Nov 19:32 share$ which xcrun/usr/bin/xcrun$ xcode-select -p/Library/Developer/CommandLineTools    Still, as I normally do, I entered the command to install and update the Developer Tools in the terminal:  xcode-select --install    This started the usual procedure: modal window to confirm, then request to accept the license agreement, followed by a progress bar. Except that it failed very quickly with an unexpected error:     Can&rsquo;t install the software because it is not currently available from the Software Update server.     I've tried several times, to no avail. It gets always stuck.    Sometimes, however, the failure causes the System Preferences to report a pending update:      If I open that preference panel it starts searching for updates, and it always finds nothing except the first time that it happened. The first time, it found this:          It literally suggested me to install the updates for macOS 10.11 and 10.13. I have no idea why.  I closed the preference without installing, and as I said it hasn't shown them again. There is also no update available in new Mac App Store.   Is this a known issue? Is there any way to resolve the problem?     Update  Of course I can download the Dev Tools for macOS 10.14 installer from .  Before installing them manually, though, I'm wondering if there is anything that's broken with the system.
I've seen many posts regarding a combinatorial proof of the following question. But for a non-combinatorial proof would the following method work? Also... is this the easiest way to arrive at a proof? It seems to be rather verbose.  Show the formula $k {n\choose k} = n {n-1 \choose k-1}$ is true for all integers $n,k$ with $0\le k \le n$.  My answer:  Observe that  $$\begin{align*} {n\choose k}&amp;= \frac {n}{k} {n-1 \choose k-1}\\ &amp;= \frac {n}{k}\left[ {n-2 \choose k-2} + {n-2 \choose k-1}\right]\\ &amp;= \frac {n}{k}\left[ \frac{(n-2)!}{(k-2)!(n-2-(k-2))!} + \frac {(n-2)!}{(k-1)!(n-2-(k-1))!}\right]\\ &amp;= \frac {n}{k}\left[ \frac{(n-2)!}{(k-2)!(n-k)!} + \frac {(n-2)!}{(k-1)!(n-k-1)!}\right]\\ &amp;= \frac{(n-1)!}{(k-1)!(n-k)!} + \frac {(n-1)!}{(k)!(n-k-1)!}\\ &amp;= \frac{(n-1)!}{(k-1)!(n-1-(k-1))!} + \frac {(n-1)!}{(k)!(n-1-k)!}\\ &amp;={n-1 \choose k-1} + {n-1 \choose k}={n \choose k}. \end{align*}$$ Before we launched our website, we had set up a "coming soon" page and google picked up the title and description from its contents. So the description in the search results said:     Coming soon! Visit example.org for updates.   It's been a few weeks since we launched our website. We've even created a sitemap and submitted it to Google. In Google Search Console, the pages have been crawled and all the pages are appearing as expected on Google, EXCEPT the homepage which is still not updated! The title and description of the homepage in google search results still says "coming soon.".***  I checked on bing too, but it appears to be fine there.  All other pages seem to be indexed fine on Google. I don't even have any crawl errors in my reports. So what seems to be the problem? I've already waited for 2 weeks. I am trying to understand the Georgi chapter of tensor methods in $SU(3)$ representations, and I don't know how to resolve the tensor product of 2 matrices in a 2 heavy quark + 2 light antiquark system. Namely:  Let the tetraquark system be:           $QQ\bar q\bar{q}$  So, those $Q$ heavy quarks interact and can be understood in the $3\bigotimes 3$ representations for $SU(3)$, and $\bar q\bar q$ can be understood as the $\bar 3\bigotimes\bar 3=3\bigoplus\bar 6$ representations for $SU(3)$.  The interaction diagram for the $Q$ heavy quarks is shown in the following scheme, which is an analogy to the Feynman Diagram where a gluon is understood to be exchanged between upper and lower arrows:  $i'\xrightarrow{(T_{a})^{i'}_{i}}i ,  {}^iQ$  $j'\xrightarrow{(T_{a})^{j'}_{j}}j ,  {}^jQ$  So, as usuall we consider the elements of $3$ representation as $u^i$, and therefore the elements of $\bar 3$ representation as $v_{j}$.  I must understand how does the following expression transform:  $(T_{a})^{i'}_{i}(T_{a})^{j'}_{j}\cdot(1/2)\cdot (w^iv^j+w^jv^i)=\Xi\cdot(1/2)\cdot(w^{i'}v^{j'}+w^{j'}v^{i'})$  In other words, how can one give the correct value of $\Xi$?  Note1: $T_a$ is understood to be the $a-ith$ generator of the associated Lie Algebra, which come from the definition of the Gell-Mann Matrices.  $(T_{a})^{i}_{j}\propto(\lambda)_{ij}$, in matrix notation.  Note2: I understand the Young Tableaux and they are not intended to be used here, so please don't try to explain this situation through the tables.   Note3: I assume this is a purely solvable mathematical problem and doesn't need a deep insight into the physical concepts...  Also requesting information about how to understand the tensor products in these cases, since I have been checking many sources but the definitions seem not clear enough. I'm writing a thesis which is an aggregate of separate articles. I have the source code for the articles and I'm using \include to include them in the main document of the thesis. So in my main.tex (thesis document), I have  \include{article1} some pages in between the two articles \include{article2}   The problem that I'm getting is with the Appendix sections. In article 1, I have at the end:  \appendix \numberwithin{equation}{section} \section{Coefficients}\label{sec:Coeffic} \subsection{Good coefficients} then comes the first line of appendix   This gives in article 1 (when  compiled separately with the article class):     A. Coefficients      A.1. Good coefficients   and equation numbers in the Appendix A as (A.1), (A.2)  which is ok and what is expected.  When I put article 1 within main.tex, I use \include command. Also, I removed the document class for article 1 and put \chapter instead.  But when I compile main.tex (the thesis document), I get the appendix sections as:     .1 Coefficients      .1.1 Good coefficients   and the equation numbers in the appendix A as (.1.1), (.1.2) etc  My article 1 is treated as a chapter in the main thesis document (main.tex) and the title and section numbers, equation numbers are preceded by A in main.tex. This is what I want.  Maybe it would be ok to get the appendix in my main.tex as     A.A. Coefficients      A.A.1 Good coefficients   and the equation numbers in the Appendix as (A.A.1), (A.A.2) etc  to denote that it refers to appendix A of paper A. First A is for the first article and second A is for first appendix. How to get this? This is a general, community wiki  question and answer pair intended to address any questions   concerning the reasons a site or specific site contents do not appear   in search engine results.      If your question was closed as a duplicate of this question and you   feel that the information provided here does not provide a sufficient   answer, please open a discussion on .   My site (or specific pages on my site) is not appearing in search engine results.  Why isn't my content indexed and what can I do about it? Using exec and tee to redirect logs to stdout and a log file in the same time In a bash script, how can I redirect all standard outputs to a log file and tee the output on the screen using exec ?  log_file="$HOME/logs/install.txt-`date +'%Y-%m-%d_%H-%M-%S'`" [ -f "$log_file" ] || touch "$log_file" exec 1&gt;&gt; $log_file 2&gt;&amp;1   This code redirect all the log to the log file but not to the screen . I'm having issues with my macbook pro OS X 10.7.5.  It used to connect to the wifi router (D-Link N300, DIR=615) no problems.  But for the past several weeks, I haven't been able to at all.  What pops up when I select my wifi network from the list:   "Failed to join "network" A connection timeout occured".   What happens when I try to enter my password manually:   "Connection timeout"   What I've tried to do as solutions:   Google Restart router by pressing reset &amp; refresh button Delete System &amp; User (Login) Keychain access Network > Gear symbol by the + and - bottom left of the screen > Set Service Order > Drag Wifi to the top Is it possible to smooth or generalize a polygon in QGIS, perhaps by using a plugin like the generalizer-plugin for lines?  I could convert my polygons to lines, smooth them and convert them back to polygons but this is not working for my polygons because of several reasons. Does the following series have a closed-form expression:  $$\sum_{k=0}^{\infty} \frac{z^k}{(k!)^2}$$  I know that it must converge because:  $$\sum_{k=0}^{\infty} \frac{z^k}{k!} = e^z$$  and the $(k!)^2$ denominator obviously increases more quickly than the $k!$ denominator.  This problem came up in computing the probability of a draw in a football match with each team's goal scoring modeled as a Poisson process.  Thanks,  John Computing the Galois group of polynomials $x^n-a \in \mathbb{Q}[x]$ I have some problems with this exercise. I don't know if it can be done. Consider the polynomial $ x^n - a \in \mathbb{Q} $ Can I compute the Galois group of this over $\mathbb{Q}$? Maybe having a nice "basis.  The splitting field is given by $\mathbb{Q}(\zeta_n,\alpha)$ , where $\zeta_n$ is a primitive root of unity , and $\alpha$ is some number such that $\alpha^n = a $. Well first of all, I want a $\underline{"good basis"}$ for the splitting field. In the sense that the minimal polynomials, of the adjoined elements, are different (in this case the computation of the galois group is very simple).  For example one easy case, it's when $a&gt;0$, then $(a)^{\frac{1}{n}} \in \mathbb{R}$ , so clearly the minimal polynomial of $(a)^{\frac{1}{n}} , \zeta_n$ are distincs, and I'm done. If $n$ is odd then , it's also easy, since one root it's also real, for example $x^3-3 $, the real root is $ \root 3 \of { - 3}  =  - \root 3 \of 3  $ , so I can consider the splitting field as $\mathbb{Q}(-\root 3 \of 3 , \zeta_3 )=\mathbb{Q}(\root 3 \of 3 , \zeta_3 )$. The difficult case is when $n$ is even and $a&lt;0$ , for example  $x^8+20$ or $x^4+20$ in some cases as in the second, there are particular cases since there exist algorithms for the Galois group of quartics, but in general. It can be done?  $\underline{Remark}$ I'm searching a $\underline{"good basis"}$ for the splitting field. In the sense that the minimal polynomials, of the adjoined elements, are different since in this case the computation of the galois group is very simple. Is there any gold standard for modeling irregularly spaced time series? I noticed that there is a definition of the pvalue in my textbook is defined says the following:    I have no idea why it is written with a supremum. I've spent hours pondering this, does anyone have enough of a background to help me with this? Thank you! I've seen papers (e.g., in Science) where the first two authors are listed in non-alphabetical order, and yet there are asterisks behind their names to say that they contributed equally.   It seems strange to me, because if the two authors are in alphabetical order, then it could be that the first author contributed more or the two contributed equally, and this can be made clear with asterisks in the paper if it's the latter case. When they're in non-alphabetical order, however, if someone only sees the author list without seeing the paper, he/she will likely assume that the first author contributed most.  So my question is: Are there particular reasons why people do that? (This  is related, but I don't think the answers there get to my question.) Why is electric field of an infinite plate constant at all points? I know from Gauss law, it is $\vec{E}=\dfrac{\sigma}{2 \epsilon_0}(\hat{n})$ at all points. But it doesn't make sense because of the inverse square nature of electric field which suggests if you move further away from the plane, electric field must reduce.   Then why is electric field of an infinite plate constant at all points? How do you use unlocked rewards after each mission in Splinter Cell: Double Agent? In the PC version of Splinter Cell: Double Agent, how can you use the rewards that you receive after each mission? For example, the shotgun attachment, or the colored night vision?  My list shows that the rewards are there, but I can not figure out how to use them. What is this type of flexible contact strip called? The LCD below is from a cheap digital clock which was (obviously) damaged (broken glass).    The electrical connection between the PCB and the display was realized with this pink strip.    Its flexible...    ...and consists of alternating rows of conductive and insulating material between the pink boarders.    [above image was altered in contrast/brightness to highlight the alternating strips]  What is this kind of connector called? Is it only used for displays?   I am pretty impressed that the connection is reliable just from the very slight pressure between the strip and the PCB. Also, its easily removable from the display. There seems to be some conductive layer on the glass, from where the signal goes into the displays internals. This connection seems to be damaged for the three rightmost signals, where the glass is broken. $$ z = 1+2i \ (complex \ number) \\ z^n = a_n + b_ni \ \ \ (a_n, b_n \in \mathbb{Z}, n \in \mathbb{N}^*) $$ Prove that $ b_{n+2} - 2b_{n+1} + 5b_n = 0$  How can I solve this? Thank you!  EDIT: Or please tell me your ideas. What should one look for when buying a used film camera? I'm planning to buy a used Nikon F5.   I have no experience with a film camera and I want to know what all should one be careful of before buying a used film camera and more specifically a Nikon F5. Using the Pigeonhole Principle to show that $2$ of any $n+1$ numbers from $\{1,2,\ldots,2n\}$ sum to $2n+1$ I am using a 36 V battey pack (10s 2.5 A each cell 3.6V.) Its maximum voltage is 42 V. I am using a STM32 microcontroller whose input is 3.3 V.  I am designing a PCB in which the power supply is drawn from the battery pack (42 V.) I would like to power the STM32 microcontroller from the battery pack power supply.  I would like to regulate 42 to 3.3 V so that I can power my STM32 microcontroller.   Which method is best to convert it either using regulator or buck converter based on the pcb designing?  Battery Specification: 10s1p   Battery pack nominal voltage: 36 V Battery pack maximum voltage: 42 V Battery pack current: 2500 mAh   Microcontroller specfication: STM32F401RCT6   Supply voltage: 3.3 to 3.6 V Supply current: 100 to 160 mA     Which method or component is best to regulate 42 V so that I can power my microcontroller with 3.3 V?